Any program can only be really useful if it complies with the Unix philosophy. Web browsers (and other tools that work with HTML, such as feed readers) are frequent violators of this principle:

• They build in way too much things into one (complex) program, dramatically decreasing the options to do things the way you want.
• They store things in way too fancy formats (XML, RDF, SQLite, etc.) which are hard to store under version control, reuse in other scripts, and so on.

The Uzbl project was started as an attempt to resolve this.

"Uzbl" is an umbrella project consisting of different flavors. In the future more things may come, but for now:

Main component meant for integration with other tools and scripts.

• Uses WebKitGtk+ for rendering and network interaction (libsoup). CSS, JavaScript, and plugin support come for free.
• Provides interfaces to get data in (commands/configuration) and out (events): stdin/stdout/fifo/Unix sockets.
• You see a WebKit view and (optionally) a status bar which gets populated externally.
• No built-in means for URL changing, loading/saving of bookmarks, saving history, keybindings, downloads, etc.
• Extra functionality: many sample scripts come with it. More are available on the Uzbl wiki or you can write them yourself.
• Entire configuration/state can be changed at runtime.
• Uzbl keeps it simple, and puts you in charge.

A minimal browser which encompasses a default configuration file, event manager and a selection of scripts which gives a comparable browsing experience to the more common browsers.

• Uses a set of scripts (mostly Python) that will fit most people, so things work out of the box; yet plenty of room for customization.
• Brings everything you expect: URL changing, history, downloads, form filling, link navigation, cookies, event management, etc.
• Advanced, customizable keyboard interface with support for modes, modkeys, multichars, variables (keywords) etc. (e.g., you can tweak the interface to be Vi-like, Emacs-like or any-other-program-like).
• Adequate default configuration.
• Focus on plaintext storage for your data and configuration files in simple, easy-to-parse formats and adherence to the XDG basedir spec.
• Visually, similar to uzbl-core except that the status bar contains useful information.
• One window per page.

A flavor of uzbl built on top of uzbl-browser which adds tabbed browsing.

• Spawns one window containing multiple tabs, each tab containing a full embedded uzbl-browser.
• Ideal as a quick and simple solution to manage multiple uzbl-browser instances without getting lost.

Throughout the documentation, when referring to uzbl we mean uzbl-core, unless otherwise specified.

The general idea is that Uzbl by default is very bare bones. You can send it commands to update settings and perform actions, through various interfaces. There is a limited, built-in default configuration. It sets a basic status bar, title format, and network connection settings. By default, there are no keybindings defined at all (default keybindings would be counterproductive when you try to customize). For examples of the possibilities what you can do, please see the sample configurations, and wiki page.

There are several interfaces to interact with Uzbl:

• uzbl --config <filename>: <filename> will be read line by line, and the commands in it will be executed. Useful to configure Uzbl at startup. If you have a file in $XDG_CONFIG_HOME/uzbl/config (this expands to ~/.config/uzbl/config on most systems), it will be automatically recognized.

• stdin: to write commands into stdin, use --config - (or -c -).

• Interactive: you can enter commands (and bind them to shortcuts, even at runtime). By default, the behaviour is modal (vi-like):

  • command mode: every keystroke is interpreted to run commands
  • insert mode: keystrokes are not interpreted so you can enter text into html forms

  There is also support for "chained" commands (multiple characters long), and keyworded commands. Also you can trigger incremental matching on commands and variables after pressing return. See the sample configuration file for more information.

  By default, copy and paste works when typing commands:

  • insert (paste X cliboard)
  • shift insert (paste primary selection buffer)

• FIFO & socket files: If enabled by setting their paths through one of the above means, you can have socket and FIFO files available which are very useful to control uzbl using external programs.

  • The advantage of the FIFO is you can write directly to it, but it's half duplex only (uzbl cannot send a response to you).

  • The socket is full duplex but a socket-compatible wrapper such as socat is needed to work with it. For example:

    echo | socat - unix-connect:

When uzbl forks a new instance (e.g., "open in new window") it will use the same command line arguments (e.g., the same --config <file>), except for --named. If you made changes to the configuration at runtime, these are not passed on to the child.

WebKit2 changes many things compared to WebKit1, some of which impact uzbl greatly. This version of uzbl only supports WebKit1 while older version tried to support both at the same time.

For a uzbl built on WebKit2 check out the next branch

Uzbl will read commands via standard input, named FIFO pipe (once fifo_dir is set) and Unix socket (once socket_dir is set). For convenience, uzbl can also be instructed to read commands from a file on startup by using the --config option. Indeed, the config file is nothing more than a list of commands with support for comments (using the # character).

Each command starts with the name of a command or a uzbl variable that expands to it. A command is terminated by a newline. Empty lines and lines that start with the hash sign (ignoring leading whitespace) are ignored by the parser. Command names are always written in lowercase.

A list of commands supported by uzbl is given here. Optional arguments are given in square brackets ([]) with literal strings options in lowercase separated by a pipe (|) character. N indicates an integer value and other uppercase values are placeholders describing what the value should be. Required options are given in angle brackets (<>). Arguments on which argument splitting is not performed are given in curly braces ({}). Variable arguments are indicated with ellipses (...). As an example:

`example1 <a|b> <N> [URI...]`

means that the command example requires its first argument which must either be a literal a or b, a second argument which is an integer, and any remaining arguments are treated as URIs. Another example:

`example2 <KEY> {VALUE}`

means that the first argument is split off used as a key and the remaining string is used verbatim. The command example2 key many args would have key as KEY and many args as VALUE.

• back [N]
  • Navigate to the Nth (default: 1) previous URI in the instance history.
• forward [N]
  • Navigate to the Nth (default: 1) next URI in the instance history.
• reload [cached|full]
  • Reload the current page. If cached is given (the default), the cache is used. If full is given, the cache is ignored.
• stop
  • Stop loading the current page. This usually means that no new network requests are made, but JavaScript can still run.
• uri {URI}
  • Tell uzbl to navigate to the given URI.
• download <URI> [DESTINATION]
  • Tell WebKit to download a URI.

• load <COMMAND>
  • Load content into the page. Supported subcommands include:
    • html <URI> <CONTENT>
      • Load content as HTML relative to a URI.
    • text <CONTENT>
      • Load content as plain text.
    • error_html <URI> <BASE_URI> <CONTENT>
      • Load content an error page (which does not appear in the forward/back list) at the given URI with the given
• frame <list|focus|reload|stop|dump|inject|get|set> [NAME]
  • Operate on frames in the current page. If not name is given, the _current frame is used. Supported subcommands include:
    • list (Unimplemented)
      • Returns a JSON object representing the of frames in the frame.
    • focus (Unimplemented)
      • Give focus to the frame.
    • reload
      • Reload the frame.
    • stop
      • Stop loading the frame.
    • save (Unimplemented)
      • Save the content frame.
    • load (Unimplemented)
      • Load content into the frame.
    • get <VARIABLE> (Unimplemented)
      • Get information about a frame.
    • set <VARIABLE> <VALUE> (Unimplemented)
      • Set information about a frame.

• cookie <add|delete|clear>
  • Manage cookies in uzbl. The subcommands work as follows:
    • add <HOST> <PATH> <NAME> <VALUE> <SCHEME> <EXPIRATION>
      • Manually add a cookie.
    • delete <DOMAIN> <PATH> <NAME> <VALUE>
      • Delete a cookie from the cookie jar.
    • clear all
      • Delete all cookies.
    • clear domain [DOMAIN...]
      • Delete all cookies matching the given domains.

• scroll <horizontal|vertical> <VALUE>
  • Scroll either the horizontal or vertical scrollbar for the page. The value may be one of:
    • begin
      • Scrolls to the beginning of the page (either left or up).
    • end
      • Scrolls to the end of the page (either right or down).
    • [-]N
      • Scrolls N "units" as defined by the scrollbar (seems to be pixels).
    • [-]N%
      • Scrolls N% of a single page.
    • N!
      • Scrolls to position N on the scrollbar (also in "units").
    • N%!
      • Scrolls to position N% on the scrollbar.
• zoom <in|out|set> [VALUE]
  • Zoom either in or out by the given amount. When setting, the value is required. If no value is given, the variable zoom_step is used.
• hardcopy [REGION]
  • Print the given region. Supported regions include:
    • page (the default)
      • Prints the entire page.
    • frame [NAME]
      • Prints the frame with the given name or the current frame if no name is given.
• geometry <SIZE>
  • Set the size of the uzbl window. This is subject to window manager policy. If the size is maximized, the uzbl window will try to maximize itself. Otherwise, the size is parsed using the WIDTHxHEIGHT±XOFFSET±YOFFSET pattern.
• snapshot <PATH> <FORMAT> <REGION> [FLAG...] (WebKit1 >= 1.9.6)
  • Saves the current page as an image to the given path. Currently supported formats include: png. Acceptable regions include:
    • visible
      • Only includes the regions of the page which are currently visible.

• plugin <COMMAND>
  • Exposes control of plugin-related information. Supported subcommands include:
    • refresh
      • Refresh the plugin database.
    • toggle [NAME...]
      • Toggle whether the given plugins are enabled (or all if none are given).
• remove_all_db
  • Remove all web databases.
• spell <COMMAND> (WebKit1 >= 1.5.1)
  • Use WebKit's spell check logic. Supported subcommands include:
    • ignore [WORD...]
      • Add the given words to the list of words to ignore.
    • learn [WORD...]
      • Teaches that the given words are spelled correctly.
    • autocorrect <WORD>
      • Returns the word as autocorrected by the checker.
    • guesses <WORD>
      • Returns the guesses for the word given by the checker as a JSON list.
• favicon <COMMAND>
  • Controls the favicon database. Supported subcommands include:
    • clear
      • Clears all cached favicons.
    • uri <URI>
      • Returns the URI of the favicon for the given URI.
    • save <URI> <PATH> (Unimplemented)
      • Saves the favicon for the given URI to a path.
• css <COMMAND>
  • Controls CSS settings in web pages. Supported subcommands include:
    • add <URI>
      • Adds a CSS file to pages when loaded. Despite the name, subsequent calls replace any previous invocation. Meaning that only one single stylesheet may be activated with this command.
    • clear Clears all user-supplied stylesheets.
• scheme <SCHEME> {COMMAND}
  • Registers a custom scheme handler for uzbl. The handler should accept a single argument for the URI to load and return HTML. When run, the output is interpreted as content at the URL with a leading line with the MIME type.
• menu <COMMAND>
  • Controls the context menu shown in uzbl. Supported subcommands include:
    • add <OBJECT> <NAME> <COMMAND>
      • Appends a new entry to the menu with the given name and runs the given command when used.
    • add_separator <OBJECT> <NAME>
      • Appends a new separator to the menu with the given name.
    • remove <NAME>
      • Remove items which have the given name.
    • query <NAME>
      • Returns the command for the item with the given name.
    • list
      • Returns the names of items in the menu as a JSON list. The list of supported objects is:
    • document
    • link
    • image
    • media

• search <COMMAND>
  • Controls WebKit's search mechanisms. Supported subcommands include:
    • option <OPTION...>
      • Manage options for searching. Options may be prefixed with + to set, - to unset, ! to toggle, and ~ to reset to its default. The default options have wrap enabled. Recognized options include:
        • wrap
          • If set, searches will wrap around when the start or end of the document is reached.
        • case_insensitive
          • If set, searches are case-insensitive.
    • options
      • Returns the current options as a JSON list.
    • clear
      • Turn off searching. The current options and search string are preserved.
    • reset
      • Turn off searching, setting the options back to the default and forgetting the search string.
    • find {STRING}
      • Search forward in the document for the string. If no string is given, the previous search string is used.
    • rfind {STRING}
      • As find, but searches backwards in the document.
    • next
      • Jumps to the next instance of the search string in the document in the same direction as the last find or rfind command.
    • prev
      • As next, but searches in the opposite direction from the last find or rfind command.
• security <SCHEME> <COMMAND> <OPTION>

  • Controls security options for a scheme. Recognized commands include:

    • get
      • Returns true if the option is set for the scheme, false otherwise.
    • set
      • Sets the option for the scheme.
    • unset (WebKit1 only)
      • Unsets the option for the scheme.

    Supported options include ("scheme" here is used as "content referenced with this scheme"):

    • local
      • If set, non-local schemes cannot link or access pages this scheme.
    • no_access
      • If set, the scheme cannot access other schemes.
    • display_isolated
      • If set, the scheme can only be displayed in the same scheme.
    • secure
      • If set, the scheme is considered "secure" and will not generate warnings when referenced by an HTTPS page.
    • cors_enabled
      • If set, the scheme is allowed to make cross-origin resource sharing.
    • empty_document
      • If set, the scheme is allowed to be committed synchronously.
• inspector <COMMAND>
  • Control the web inspector. Supported subcommands include:
    • show
      • Show the web inspector.
    • close
      • Close the web inspector.
    • coord <X> <Y>
      • Inspect the page at the given coordinate. The coordinate is relative to the current viewport.
    • node <NODE> (WebKit1 >= 1.3.17) (Unimplemented)
      • Inspect the node which matches the given CSS selector string. If multiple nodes match, the first one is used.

• js <CONTEXT> <file|string> <VALUE>
  • Run JavaScript code. If file is given, the value is interpreted as a path to a file to run, otherwise the value is executed as JavaScript code. Currently supported contexts include:
    • uzbl
      • Run the code in the uzbl context. This context does not (currently) have access to the page's contents.
    • clean
      • Create a new context just for this command. This is the most secure option and should be preferred where possible.
    • frame
      • Run the code in the current frame's context.
    • page
      • Run the code in the current page's context. Be careful putting code into this context since anything in here may be hijacked by a malicious webpage. The context is cleared on each page load.
• spawn <COMMAND> [ARGUMENT...] (WILL CHANGE)

  • Spawn a command on the system with the given arguments. This ignore the stdout of the command. Will become spawn async in the future. The first argument command may use the following format to support fallback directories:

    dir1:dir2:dir3:subpath
    

    This will try @{dir1}@{subpath} followed by @{dir2}@{subpath}and so on. The first file which exists is used. If none of them exist, it is used as the command verbatim and thePATH` environment variable is used.

• spawn_sync <COMMAND> [ARGUMENT...] (DEPRECATED)
  • Spawn a command on the system synchronously with the given arguments and return its stdout. Will become spawn async in the future.
• spawn_sync_exec <COMMAND> [ARGUMENT...] (DEPRECATED)
  • Spawn a command synchronously and then execute the output as uzbl commands. This will disappear in the future and the command should communicate to uzbl over either the FIFO or the socket.
• spawn_sh <COMMAND> [ARGUMENT...] (DEPRECATED)
  • Spawn a command using the default shell. This is deprecated for spawn @shell_cmd ....
• spawn_sh_sync <COMMAND> [ARGUMENT...] (DEPRECATED)
  • Spawn a command using the default shell. This is deprecated for spawn_sync @shell_cmd ....

• chain <COMMAND...>
  • Execute a chain of commands. This is useful for commands which should not have any interruption between them.
• include {PATH}
  • Execute a file as a list of uzbl commands.
• exit
  • Closes uzbl.

• set <NAME> {VALUE}
  • Set a variable to the given value. Unsetting a variable is not possible (currently). Set it to the empty string (behavior is the same).
• toggle <VARIABLE> [OPTION...]
  • Toggles a variable. If any options are given, a value is chosen from the list, the option following the current value is used, defaulting to the first value if the current value is not found. Without any options, non-strings are toggled between 0 and 1 (if it is neither of these values, 0 is set). User values are set to the empty string unless they are 0 or 1 in which case the other is set. If the variable does not exist, it is set to 1.
• print {STRING}
  • Performs variable expansion on the string and returns the value.
• dump_config
  • Dumps the current config (which may have been changed at runtime) to stdout. Uses a format which can be piped into uzbl again or saved as a config file.
• dump_config_as_events
  • Dump the current config as a series of VARIABLE_SET events, which can be handled by an event manager.
• event <NAME> [ARGUMENTS...]
  • Send a custom event.
• request <NAME> <COOKIE> [ARGUMENTS...]
  • Send a synchronous request and returns the result of the request. This is meant to be used for synchronous communication between the event manager and uzbl since spawn_sync is not usable to talk to the event manager.
• choose <NAME> <COOKIE> [ARGUMENTS...]
  • Send a synchronous choose and returns the result of the request. This is meant to implement the file_chooser_handler and color_chooser_handler where a result should be waited upon indefinitely. This will hang uzbl if it is not replied to.

Uzbl has a lot of internal variables and constants. You can get the values (see the print command), and for variables you can also change the value at runtime. Some of the values can be passed at start up through command line arguments, others need to be set by using commands (e.g., in the configuration file).

• Some variables have callback functions which will get called after setting the variable to perform some additional logic (see below).
• Besides the builtin variables you can also define your own ones and use them in the exact same way as the builtin ones.

Integer variables may be negative, boolean values should be either 0 or 1. Commands are variables intended to be executed as uzbl commands. All user variables are treated as strings.

• verbose (integer) (default: 0)
  • Controls the verbosity of uzbl as it runs.
• frozen (boolean) (default: 0)
  • If non-zero, all network requests and navigation are blocked. This is useful for blocking pages from redirecting or loading any content after the core content is loaded. Network connections which have already started will still complete.
• print_events (boolean) (default: 0)
  • If non-zero, events will be printed to stdout.
• handle_multi_button (boolean) (default: 0)
  • If non-zero, uzbl will intercept all double and triple clicks and the page will not see them.

• fifo_dir (string) (no default)
  • Sets the directory for the FIFO. If set previously, the old FIFO is removed.
• socket_dir (string) (no default)
  • Sets the directory for the socket. If set previously, the old socket is removed.

• navigation_handler (command) (no default)
  • The command to use when determining what to do when navigating to a new URI. It is passed the URI as an extra argument. If the command returns a string with the first line containing only the word USED, the navigation is ignored.
• request_handler (command) (no default)
  • The command to use when a new network request is about to be initiated. The URI is passed as an argument. If the command returns a non-empty string, the first line of the result is used as the new URI. To cancel a request, use the URI about:blank.
  • NOTE: Do not use request in WebKit1 as this is called synchronously and will just pause uzbl-core until the request timeout occurs.
• download_handler (command) (no default) (synchronous in WebKit1)
  • The command to use when determining where to save a downloaded file. It is passed the URI, suggested filename, content type, and total size as arguments. If a destination is known, it is passed as well. The result is used as the final destination. If it is empty, the download is cancelled.
  • NOTE: Do not use request in WebKit1 as this is called synchronously and will just pause uzbl-core until the request timeout occurs.
• mime_handler (command) (no default) (WebKit1 only)
  • The command to use when determining what to do with content based on its mime type. It is passed the mime type and disposition as arguments.
• authentication_handler (command) (no default) (WebKit1 only)
  • The command to use when requesting authentication.
• permission_handler (command) (no default)
  • The command to use when WebKit requesting permission for an action.
• file_chooser_handler (command) (no default) (WebKit >= 1.9.4)
  • The command to use when a web page requests a file. By default, the GTK widget file dialog.
• shell_cmd (string) (default: sh -c)
  • The command to use as a shell. This is used in the spawn_sh and sync_sh commands as well as @()@ expansion.
• enable_builtin_auth (boolean) (default: 0)
  • If non-zero, WebKit will handle HTTP authentication dialogs.

• icon (string) (no default)
  • The path to an image to use as an icon for uzbl. Overrides icon_name when set.
• icon_name (string) (no default)
  • The name of an icon use as an icon for uzbl. Overrides icon when set.
• window_role (string) (no default)
  • Sets the role of the window. This is used to hint to the window manager how to handle the window.
• auto_resize_window (boolean) (default: 0) (WebKit1 only)
  • If non-zero, WebKit will try to honor JavaScript moving the window. May still be blocked by window manager policy.

• show_status (boolean) (default: 1)
  • If non-zero, the status bar is shown.
• status_top (boolean) (default: 0)
  • If non-zero, the status bar is placed above the page, otherwise it is placed below.
• status_format (string) (default: <b>@[@TITLE]@</b> - @[@uri]@ - <span foreground="#bbb">@NAME</span>)
  • The format string of the content in the status bar.
• status_format_right (string) (no default)
  • The format string of the content in right side of the status bar. The right side is elided if the left side overflows.
• status_background (string) (no default)
  • The background color of the status bar. Most common formats supported.
• title_format_long (string (default: @keycmd @TITLE - Uzbl browser <@NAME> > @SELECTED_URI)
  • `The title to use when no status bar is shown.
• title_format_short (string (default: @TITLE - Uzbl browser <@NAME>)
  • `The title to use when the status bar is shown.

• default_context_menu (boolean) (default: 0)
  • If non-zero, display the default context menu, ignoring any custom menu items.

• print_backgrounds (boolean) (default: 1)
  • If non-zero, print backgrounds when printing pages.

• proxy_url (string) (no default) (WebKit1 only)
  • If set, the value is used as a network proxy.
• max_conns (integer) (default: 100) (WebKit1 only)
  • The maximum number of connections to initialize total.
• max_conns_host (integer) (default: 6) (WebKit1 only)
  • The maximum number of connections to use per host.
• http_debug (enumeration) (default: none) (WebKit1 only)
  • Debugging level for HTTP connections. Acceptable values include:
    • none
    • minimal
    • headers
    • body
• ssl_ca_file (string) (no default) (WebKit1 only)
  • The path to the CA certificate file in PEM format to use for trusting SSL certificates. By default, the system store is used.
• ssl_policy (enumeration) (default: fail)
  • The policy to use for handling SSL failures. Acceptable values include:
    • ignore
    • fail
• cache_model (enumeration) (default: unknown)
  • The model to use for caching content. Acceptable values include:
    • document_viewer
      • Disables all caching.
    • web_browser
      • Caches heavily to attempt to minimize network usage.
    • document_browser
      • Caches moderately. This is optimized for navigation of local resources.

• enable_private (boolean) (default: 0)
  • If non-zero, enables WebKit's private browsing mode. Also sets the UZBL_PRIVATE environment variable for external plugins. DNS prefetching is separate from this; see the enable_dns_prefetch variable. It is currently experimental in WebKitGtk itself.
• permissive (boolean) (default: 0)
  • If non-zero, permission will be granted by default (if enable_private is 0) if permission_handler is either not set or returns an invalid value.
• enable_universal_file_access (boolean) (default: 0) (WebKit1 only)
  • If non-zero, content accessed via the file scheme will be allowed to access all other content.
• enable_cross_file_access (boolean) (default: 0) (WebKit1 only)
  • If non-zero, content accessed via the file scheme will be allowed to access other file content.
• enable_hyperlink_auditing (boolean) (default: 0)
  • If non-zero, <a ping> will be allowed in WebKit.
• cookie_policy (enumeration) (default: always)
  • Sets the cookie policy for WebKit. Acceptable values include:
    • always
    • never
    • first_party
      • Blocks third-party cookies.
• enable_dns_prefetch (boolean) (default: 1) (WebKit >= 1.3.13)
  • If non-zero, WebKit will prefetch domain names while browsing.
• display_insecure_content (boolean) (default: 1) (WebKit1 >= 1.11.2)
  • If non-zero, HTTPS content will be allowed to display content served over HTTP.
• run_insecure_content (boolean) (default: 1) (WebKit1 >= 1.11.2)
  • If non-zero, HTTPS content will be allowed to run content served over HTTP.
• maintain_history (boolean) (default: 1) (WebKit1 only)
  • If non-zero, WebKit will maintain a back/forward list.

• profile_js (boolean) (default: 0) (WebKit1 only)
  • If non-zero, the inspector will profile running JavaScript. Profiles are available as the Console.profiles variable in JavaScript.
• profile_timeline (boolean) (default: 0) (WebKit1 only)
  • If non-zero, the inspector will profile network activity.

• forward_keys (boolean) (default: 0)
  • If non-zero, uzbl will pass keypresses to WebKit.
• useragent (string) (no default)
  • The string to send as the User-Agent HTTP header. Setting this variable does not update the useragent in JavaScript as seen by the navigator.userAgent variable.
• accept_languages (string) (no default)
  • The list of languages to send with the Accept-Language HTTP header. In WebKit1, if set to auto, the list will be constructed from the system.
• zoom_level (double) (default: 1.0)
  • The current zoom level of the page.
• zoom_step (double) (default: 0.1)
  • The amount to step by default with the zoom in and zoom out commands. Must be greater than 0.
• zoom_text_only (boolean) (default: 0)
  • If non-zero, only text will be zoomed on a page.
• caret_browsing (boolean) (default: 0)
  • If non-zero, pages may be navigated using the arrows to move a cursor (similar to a word processor).
• enable_frame_flattening (boolean) (default: 0) (WebKit >= 1.3.5)
  • If non-zero, frames will be expanded and collapsed into a single scrollable area.
• enable_smooth_scrolling (boolean) (default: 0) (WebKit >= 1.9.0)
  • If non-zero, scrolling the page will be smoothed.
• page_view_mode (enumeration) (default: web)
  • How to render content on a page. Acceptable values include:
    • web
      • Render content as a web page.
    • source
      • Display the source of a page as plain text.
• transparent (boolean) (default: 0) (WebKit1 only)
  • If non-zero, the web page will have a transparent background rather than a solid color.
• window_view_mode (enumeration) (default: windowed) (WebKit1 >= 1.3.4)
  • Sets the value web pages will see for how the content is presented to the user. Acceptable values include:
    • windowed
    • floating
    • fullscreen
    • maximized
    • minimized
• enable_fullscreen (boolean) (default: 0) (WebKit >= 1.3.4)
  • If non-zero, Mozilla-style JavaScript APIs will be enabled for JavaScript.
• editable (boolean) (default: 0)
  • If non-zero, web pages will be editable similar to a WYSIWYG editor.

• enable_scripts (boolean) (default: 1)
  • If non-zero, JavaScript will be allowed to execute on web pages.
• javascript_windows (boolean) (default: 0)
  • If non-zero, JavaScript in a page will be allowed to open windows without user intervention.
• javascript_dom_paste (boolean) (default: 0) (WebKit1 only)
  • If non-zero, JavaScript in a page will be able to paste content from the system clipboard.
• javascript_clipboard (boolean) (default: 0) (WebKit >= 1.3.0)
  • If non-zero, JavaScript in a page will be able to access content in the system clipboard directly.

• autoload_images (boolean) (default: 1)
  • If non-zero, images will automatically be loaded.
• autoshrink_images (boolean) (default: 1) (WebKit1 only)
  • If non-zero, stand-alone images will be resized to fit within the window.
• use_image_orientation (boolean) (default: 0) (WebKit1 only)
  • If non-zero, image orientation tags will be used to reorient images once loaded.

• enable_spellcheck (boolean) (default: 0)
  • If non-zero, spell checking will be enabled in text entries.
• spellcheck_languages (string) (no default)
  • A comma-separated list of languages to use for spell checking. Must be set for enable_spellcheck to actually mean anything.

• resizable_text_areas (boolean) (default: 1)
  • If non-zero, text area form elements will be resizable with a drag handle.
• enable_spatial_navigation (boolean) (default: 0)
  • If non-zero, the arrow keys will navigate between form elements.
• editing_behavior (enumeration) (default: unix) (WebKit1 only)
  • Sets the behavior of text area elements to behave closer to native widgets on different platforms. Acceptable values include:
    • mac
    • unix
    • windows
• enable_tab_cycle (boolean) (default: 1)
  • If non-zero, the tab key will navigate between form elements, otherwise it will always be interpreted as an insertion of a tab character.

• default_encoding (string) (default: iso-8859-1)
  • The encoding to assume pages use if not indicated in HTTP headers.
• custom_encoding (string) (no default)
  • If non-empty, the value is used to override any other encoding used for the page. Causes the page to be reloaded. Set to the empty string to clear any custom encoding.
• enforce_96_dpi (boolean) (default: 0) (WebKit1 only)
  • If non-zero, the display will be assumed to be 96-dpi.

• default_font_family (string) (default: sans-serif)
  • The font family to use by default for all text.
• monospace_font_family (string) (default: monospace)
  • The font family to use by default for monospace text.
• sans_serif_font_family (string) (default: sans-serif)
  • The font family to use by default for sans serif text.
• serif_font_family (string) (default: serif)
  • The font family to use by default for serif text.
• cursive_font_family (string) (default: serif)
  • The font family to use by default for any cursive text.
• fantasy_font_family (string) (default: serif)
  • The font family to use by default for any fantasy text.

Note: font sizes are in points.

• minimum_font_size (integer) (default: 5)
  • The minimum font size to use for text.
• minimum_logical_font_size (integer) (default: 5)
  • The minimum logical font size to use for text. This is the size after any transforms or "smaller" CSS specifications.
• font_size (integer) (default: 12)
  • The default font size for text.
• monospace_size (integer) (default: 10)
  • The default font size for monospace text.

• enable_plugins (boolean) (default: 1)
  • If non-zero, plugins will be enabled on the page.
• enable_java_applet (boolean) (default: 1)
  • If non-zero, Java will be enabled for the page. This includes the applet HTML tag which is not controlled by the enable_plugins variable.
• enable_webgl (boolean) (default: 0) (WebKit >= 1.3.14)
  • If non-zero, WebGL will be enabled.
• enable_webaudio (boolean) (default: 0) (WebKit >= 1.7.5)
  • If non-zero, the WebAudio API will be enabled.
• enable_3d_acceleration (boolean) (default: 0) (WebKit1 >= 1.7.90)
  • If non-zero, the GPU will be used to render animations and 3D CSS transforms.
• enable_inline_media (boolean) (default: 1) (WebKit >= 1.9.3)
  • If non-zero, media playback within a page will be enabled, otherwise, only fullscreen playback is allowed.
• require_click_to_play (boolean) (default: 0) (WebKit >= 1.9.3)
  • If non-zero, media may automatically play on a page, otherwise a user interaction is required to even load the media.
• enable_css_shaders (boolean) (default: 0) (WebKit1 >= 1.11.1 and < 2.3.5)
  • If non-zero, CSS shaders will be enabled.
• enable_media_stream (boolean) (default: 0) (WebKit1 >= 1.11.1)
  • If non-zero, the Media Stream API will be enabled.
• enable_media_source (boolean) (default: 0) (WebKit >= 2.3.3)
  • If non-zero, the MediaSource API will be enabled.

• enable_database (boolean) (default: 1)
  • If non-zero, the HTML5 client-side SQL API for JavaScript is enabled.
• enable_local_storage (boolean) (default: 1)
  • If non-zero, the HTML5 local storage API is enabled.
• enable_pagecache (boolean) (default: 0)
  • If non-zero, WebKit will "freeze" pages when navigating to optimize back/forward navigation. See this article for more information.
• enable_offline_app_cache (boolean) (default: 1)
  • If non-zero, HTML5 web application cache support will be enabled. This allows web applications to run locally without a network connection.
• app_cache_size (size) (default: [no quota]) (WebKit1 >= 1.3.13)
  • The maximum size (in bytes) of the local application cache.
• web_database_directory (string) (default: $XDG_DATA_HOME/webkit/databases) (WebKit1 only)
  • Where to store web databases.
• web_database_quota (size) (default: 5242880) (WebKit1 only)
  • The maximum size (in bytes) of web databases. (Note: It is unclear if this is a total quota or per-database quota.)
• local_storage_path (string) (default: $XDG_DATA_HOME/webkit/databases) (WebKit1 >= 1.5.2)
  • Where to store HTML5 localStorage data.

• enable_site_workarounds (boolean) (default: 0)
  • If non-zero, WebKit will use site-specific rules to workaround known broken behavior.

Constants may not be assigned to. When dumping variables using dump_config, they are written as comments.

• inspected_uri (string) (WebKit >= 1.3.17)
  • The URI which the inspector is currently focusing on.
• current_encoding (string) (WebKit1 only)
  • The encoding of the current page.
• geometry (string)
  • A string giving the current window geometry of uzbl in <width>x<height>+<xoffset>+<yoffset> format.
• plugin_list (string) (WebKit1 >= 1.3.8)
  • A JSON-formatted list describing loaded plugins.
• is_online (boolean)
  • If non-zero, a network is available (not necessarily the Internet).
• is_playing_audio (boolean)
  • If non-zero, audio is playing.
• uri (string)
  • The current top-level URI of the view.
• embedded (boolean)
  • If non-zero, uzbl is embedded in another window, otherwise it is stand-alone.
• WEBKIT_MAJOR (integer)
  • The major version of WebKit at runtime.
• WEBKIT_MINOR (integer)
  • The minor version of WebKit at runtime.
• WEBKIT_MICRO (integer)
  • The micro version of WebKit at runtime.
• WEBKIT_UA_MAJOR (integer)
  • The major useragent version of WebKit at compile time.
• WEBKIT_UA_MINOR (integer)
  • The minor useragent version of WebKit at compile time.
• HAS_WEBKIT2 (boolean)
  • If non-zero, uzbl is using WebKit2.
• ARCH_UZBL (string)
  • The architecture uzbl is compiled for.
• COMMIT (string)
  • The commit string of uzbl at compiled time.
• TITLE (string)
  • The title of the current page.
• SELECTED_URI (string)
  • The URI of the link is hovering over; empty if there is no link.
• NAME (string)
  • The name of the uzbl instance (defaults to the pid).
• PID (integer)
  • The process ID of uzbl.
• _ (string)
  • The last result from a command.

Variable expansion works similarly to shell interpreters (sh, bash, etc.). This means you can construct strings with uzbl variables in them and have uzbl replace the variable name with its contents.

In order to let uzbl know what to expand you'll need to prepend @ to the variable name:

print The variable \@show_status contains @show_status

The above example demonstrates two things:

• \ is treated as escape character and will use the character immediately following it literally this means \@show_status will not expand to the variable content but be rather printed as @show_status
• prepending the variable with @ will expand to its contents

As in the shell you can use @{uzbl_var} to denote the beginning/end of the variable name in cases where it is not obvious what belongs to the name and what not, e.g., print @{show_status}foobar

There are multiple constructs for more complex expansion.

• @(+command arg1 arg2)@
  • This is equivalent to running spawn_sync command arg1 arg2 and is replaced by the first line of its stdout.
• @(command arg1 arg2)@
  • This is equivalent to running spawn_sh_sync command arg1 arg2 and is replaced by the first line of its stdout.

• @/+file/@
  • This is equivalent to running include file and is replaced by its result.
• @/command arg1 arg2/@
  • This is equivalent to running command arg1 arg2 and is replaced by its result.

• @*+javascript_file*@
  • This is equivalent to running js uzbl file javascript_file and is replaced by its result.
• @*javascript*@
  • This is equivalent to running js uzbl string javascript and is replaced by its result.
• @<+javascript_file>@
  • This is equivalent to running js page file javascript_file and is replaced by its result.
• @<javascript>@
  • This is equivalent to running js page string javascript and is replaced by its result.
• @-+javascript_file-@
  • This is equivalent to running js clean file javascript_file and is replaced by its result.
• @-javascript-@
  • This is equivalent to running js clean string javascript and is replaced by its result.

• @[string]@
  • This escapes string for XML entities. This is most useful when using page-defined strings in the status_bar variable.

Uzbl has a JavaScript API available via the js uzbl command. There is a global uzbl object can control uzbl through two properties: variables and commands. For example, to set the verbose variable:

uzbl.variables.verbose = 1

To call the back command:

uzbl.commands.back()

All arguments to commands be converted to strings, so {} will appear to commands as [object Object], not JavaScript objects.

Currently, access to the webpage is not available through the uzbl context. This is currently impossible with WebKit2 (since even uzbl does not have access to the page's JavaScript context) and crashes WebKit1.

The contents of the status bar can be customized by setting the status_format variable. The contents of the window title can be customized by setting the title_format_short variable (which is used when the status bar is displayed) and the title_format_long variable (which is used when the status bar is not displayed). Their values can be set using the expansion and substitution techniques described above.

These variables are expanded in multiple stages; once when the variable is set, and again every time that the status bar or window title are updated. Expansions that should be evaluated on every update need to be escaped:

set title_format_short = @(date)@
# this expansion will be evaluated when the variable is set.
# the title will stay constant with the date that the variable was set.

set title_format_short = \@(date)\@
# this expansion will be evaluated when the window title is updated.
# the date in the title will change when you change pages, for example.

set title_format_short = \\\@(date)\\\@
# the title will stay constant as a literal "@(date)@"

The status_format and status_format_right variables can contain Pango markup . In these variables, expansions that might produce the characters <, & or > should be wrapped in @[]@ substitutions so that they don't interfere with the status bar's markup; see the sample config for examples.

You can use external scripts with Uzbl the following ways:

• Let uzbl call them. These scripts are called "handlers" in the uzbl config. These are typically used for policy requests so that behavior can be controlled with external logic.
• Call them yourself from inside uzbl. You can bind keys with this. Examples: add new bookmark, load new URL.
• You could also use xbindkeys or your WM config to trigger scripts if uzbl does not have focus.

Scripts called by uzbl (the commands starting with spawn) have access to the following environment variables:

• $UZBL_CONFIG
  • The configuration file loaded by this uzbl instance.
• $UZBL_PID
  • The process ID of this uzbl instance.
• $UZBL_XID
  • The X Windows ID of the process.
• $UZBL_FIFO
  • The filename of the FIFO being used, if any.
• $UZBL_SOCKET
  • The filename of the Unix socket being used, if any.
• $UZBL_URI
  • The URI of the current page.
• $UZBL_TITLE
  • The current page title.
• $UZBL_PRIVATE
  • Set if the enable_private variable is non-zero, unset otherwise.

Handler scripts (download_handler, navigation_handler, request_handler, mime_handler, authentication_handler, permission_handler, tls_error_handler, file_chooser_handler, and color_chooser_handler) are called with special arguments:

• download handler

  1. url
  • The URL of the item to be downloaded.
  2. suggested_filename
  • A filename suggested by the server or based on the URL.
  3. content_type
  • The mimetype of the file to be downloaded.
  4. total_size
  • The size of the file to be downloaded in bytes. This may be inaccurate.
  5. destination_path
  • This is only present if the download was started explicitly using the download command. If it is present, this is the path that the file should be saved to. A download handler using WebKit's internal downloader can just echo this path and exit when this argument is present.

• navigation handler

  1. uri
  • The URI of the page to be navigated to.
  2. src_frame
  • The name of the frame which is targeted for the navigation.
  3. dest_frame
  • The name of the frame which is targeted for the navigation.
  4. type
  • The type of navigation that triggered the request. Known values include:
    • link
    • form_submission
    • back_forward
    • reload
    • form_resubmission
    • other
    • unknown
  5. button
  • The mouse button used for the navigation (or 0 if a mouse was not used).
  6. modifiers
  • The modifiers used for the navigation. This uses the same format as the KEY_PRESS and KEY_RELEASE events.
  7. is_gesture
  • true if the action was triggered by a gesture, false otherwise.

• request handler

  1. uri
  • The URI of the resource which is being requested.
  2. can_display
  • One of can_display, cant_display, or unknown to indicate whether WebKit knows how to display the data given its MIME type (unknown means that uzbl was unable to determine the answer).
  3. frame
  • The name of the frame requesting the resource.
  4. redirect
  • Whether the request is a redirect or not

• mime handler

  1. mime_type
  • The mime type of the resource.
  2. disposition
  • The disposition of the resource. Empty if unknown.

• authentication handler

  1. host
  • The host requesting authentication.
  2. realm
  • The realm requesting authentication.
  3. retry
  • Either retrying or initial depending on whether this request is a retrial of a previous request.
  4. scheme
  • The authentication scheme being used. Known values include:
    • default
    • http_basic
    • http_digest
    • html_form
    • ntlm
    • negotiate
    • client_certificate_requested
    • server_trust_evaluation_requested
  5. proxy
  • Either proxy if a proxy is requesting authentication or origin if a remote server is.
  6. port
  • The port connected to.
  7. save
  • Either can_save or cant_save depending on whether WebKit itself can save the credentials.

• permission handler

  1. uri
  • The URI requesting permission.
  2. action
  • The data or action WebKit is requesting permission for. Known values include:
    • geolocation
    • unknown
  3. description
  • A description for the request (if available).

• tls error handler

  1. host
  • The host which failed TLS verification.
  2. flags
  • A comma-separated list of the reasons the host failed TLS verification. Known flags include:
    • unknown_ca
    • bad_identity
    • not_activated
    • expired
    • revoked
    • insecure
    • error
  3. cert_info
  • A JSON object with information describing the certificate.

• file chooser handler

  1. mode
  • Either multiple or single for whether a single file or multiple files were requested.
  2. mimetypes
  • A comma-separated list of mimetypes requested.

• color chooser handler

  1. region
  • The region of the element requesting a color in the WIDTHxHEIGHT+X+Y format.

As mentined before, the contents of the window title can be customized by setting the title_format_short variable and the title_format_long variable (see above to figure out when each of them is used). You can also set icon variable to path of the icon file. Some advanced window managers can also take WM_WINDOW_ROLE in account, which can be set by modifying window_role variable.

Uzbl does not automatically use the current page's favicon as its icon. This can, however, be done with external scripts.

Uzbl sets the UZBL_URI property on its window which is always the uri of the page loaded into uzbl, except for web inspector windows which does not have the property.

Unlike commands, events are not handled in uzbl itself, but are dispatched asynchronously through a text stream on stdout and/or through a socket. You'll usually use uzbl by connecting it to a so-called "event manager" (EM).

An EM is a privileged communicator with uzbl. EM sockets are given on the command line via the --connect-socket argument. EM sockets receive requests in addition to events. All sockets receive event output. Please be aware that events contain sensitive information such as cookie data and keystrokes (e.g., passwords).

An example EM is shipped with uzbl called uzbl-event-manager. See its documentation for more.

Many of the features of larger browsers are intended to be implemented via an EM. The EM receives all events and requests from uzbl and can implement history, keybindings, cookie management, and more. For more on the EM shipped with uzbl, see its documentation

Events are reported in the following format.

 EVENT <NAME> <EVENT_NAME> {DETAILS}

Events are line-oriented, so newlines are not supported within events.

Requests use the following format:

REQUEST-<COOKIE> <REQUEST_NAME> [ARGUMENTS...]

Only EM sockets receive REQUEST lines. Currently, if a reply is not received within one second from uzbl sending a request, uzbl will continue without a reply. This is because the request blocks the GUI thread. Replies to a request use the following format:

REPLY-<COOKIE> <REPLY>

If the cookie does not match the cookie from the request, uzbl will ignore it.

Uzbl will report various events by default. All of these events are part of uzbl itself and will be emitted based on what is happening within uzbl-core.

• NAVIGATION_STARTING <URI> <SRCFRAME> <DESTFRAME> <TYPE>
  • Sent when a main navigation is requested for a frame. See navigation_handler for the types available.
• LOAD_START
  • Sent when a main page navigation is started. This is before WebKit even looks at the URI, so the name, protocol, or port may still be invalid.
• LOAD_REDIRECTED <URI>
  • Sent when the main page navigation has been redirected to a new URI.
• LOAD_COMMIT <URI>
  • Sent when the main page navigation has been committed and the network request has been sent to the server.
• LOAD_PROGRESS <PROGRESS>
  • Sent when the load percentage changes. The progress is in percentage.
• LOAD_CANCELLED <URI>
  • Sent when the user has cancelled a load (e.g., by setting the URI in the middle of another load).
• LOAD_ERROR <URI> <CODE> <MESSAGE>
  • Sent when WebKit has failed to load a page.
• LOAD_FINISH <URI>
  • Sent when a page navigation is complete. All of the top-level resources have been retrieved by this point.
• REQUEST_QUEUED <URI> (WebKit1 only)
  • Sent when a request is queued for the network.
• REQUEST_STARTING <URI>
  • Sent when a request has been sent to the server.
• REQUEST_FINISHED <URI>
  • Sent when a request has completed.

• KEY_PRESS <MODIFIERS> <KEY>
  • Sent when a key (e.g., Shift, Ctrl, etc.) is pressed. The key is in UTF-8. This event is also used for mouse clicks which use the format <REP>Button<VALUE> which would be 2Button1 for a double click of the main mouse button (rep is empty for single clicks). Multiple clicks usually only show as a KEY_RELEASE event due to GDK implementation details.
• KEY_RELEASE <MODIFIERS> <KEY>
  • Sent when a key (e.g., Shift, Ctrl, etc.) is released. The key is in UTF-8.
• MOD_PRESS <MODIFIERS> <MODIFIER>
  • Sent when a modifier (e.g., Shift, Ctrl, etc.) is pressed.
• MOD_RELEASE <MODIFIERS> <MODIFIER>
  • Sent when a modifier (e.g., Shift, Ctrl, etc.) is released.

• BUILTINS <COMMANDS>
  • On startup, uzbl will emit this event with a JSON list of the names of all commands it understands.
• COMMAND_ERROR <REASON>
  • Sent when uzbl cannot execute a command.
• COMMAND_EXECUTED <NAME> [ARGS...]
  • Sent after a command has executed.
• FILE_INCLUDED <PATH>
  • Sent after a file is included.

• FIFO_SET
  • Sent uzbl opens a communication FIFO.
• SOCKET_SET <PATH>
  • Sent uzbl opens a communication socket.
• INSTANCE_START <PID>
  • Sent on startup.
• PLUG_CREATED <ID>
  • Sent if uzbl is started in plug mode. The ID is for the Xembed socket.
• INSTANCE_EXIT <PID>
  • Sent before uzbl quits. When this is sent, uzbl has already stopped listening on all sockets.
• VARIABLE_SET <NAME> <str|int|ull|double> {VALUE}
  • Sent when a variable has been set. Not all variable changes cause a VARIABLE_SET event to occur (e.g., any variable managed by WebKit behind the scenes does not trigger this event).

• BLUR_ELEMENT <NAME> (WebKit1 only)
  • Sent when an element loses focus.
• FOCUS_ELEMENT <NAME> (WebKit1 only)
  • Sent when an element gains focus.
• LINK_HOVER <URI> <TITLE>
  • Sent when a link is hovered over using the mouse.
• LINK_UNHOVER <URI>
  • Sent when a link is hovered over using the mouse. The URI is the previously hovered link URI.
• FORM_ACTIVE <BUTTON>
  • Sent when a form element has gained focus because of a mouse click.
• ROOT_ACTIVE <BUTTON>
  • Sent when the background page has been clicked.
• SCROLL_HORIZ <VALUE> <MIN> <MAX> <PAGE>
  • Sent when the page horizontal scroll bar changes. The min and max values are the bounds for scrolling, page is the size that fits in the viewport and the value is the current position of the scrollbar.
• SCROLL_VERT <VALUE> <MIN> <MAX> <PAGE>
  • Similar to SCROLL_HORIZ, but for the vertical scrollbar.
• TITLE_CHANGED <TITLE>
  • Sent when the page title changes.

• GEOMETRY_CHANGED <GEOMETRY>
  • Sent when the geometry changes.
• WEBINSPECTOR <open|close>
  • Sent when the web inspector window is opened or closed.
• REQ_NEW_WINDOW <URI>
  • Sent when a new window is being requested.
• CLOSE_WINDOW
  • Sent when uzbl is closing its window.
• FOCUS_LOST
  • Sent when uzbl loses the keyboard focus.
• FOCUS_GAINED
  • Sent when uzbl gains the keyboard focus.

• DOWNLOAD_STARTED <DESTINATION>
  • Sent when a download to the given URI has started.
• DOWNLOAD_PROGRESS <DESTINATION> <PROGRESS>
  • Sent when progress for a download has been updated. The progress is a value between 0 and 1.
• DOWNLOAD_ERROR <DESTINATION> <REASON> <CODE> <MESSAGE>
  • Sent when a download has an error.
• DOWNLOAD_COMPLETE <DESTINATION>
  • Sent when a download has completed.

• ADD_COOKIE <DOMAIN> <PATH> <NAME> <VALUE> <SCHEME> <EXPIRATION>
  • Sent when a cookie is added.
• DELETE_COOKIE <DOMAIN> <PATH> <NAME> <VALUE> <SCHEME> <EXPIRATION>
  • Sent when a cookie is deleted.

uzbl is invoked as

uzbl-core [ARGUMENTS] [URI]

where arguments and uri are both optional. arguments can be:

• -v, --verbose
  • Sets verbose to be non-zero.
• -n, --named=NAME
  • Name of the current instance (defaults to Xorg window id or random for GtkSocket mode).
• -c, --config=FILE
  • Path to config file or - for stdin.
• -s, --xembed-socket=SOCKETID
  • Xembed socket ID.
• --connect-socket=CSOCKET
  • Connect to server socket for event managing.
• -p, --print-events
  • Sets print_events to be non-zero.
• -g, --geometry=GEOMETRY
  • Runs geometry GEOMETRY with the given value on startup. Ignored if uzbl is embedded.
• -V, --version
  • Print the version and exit.
• --web-extensions-dir
  • Directory that will be searched for webkit extensions
• --display=DISPLAY
  • X display to use.
• --help
  • Display help.

uzbl-core scheme://address will work as you expect. If you don't provide the scheme:// part, it will check if the argument is an existing file in the filesystem, if it is, it will prepend file://, if not, it will prepend http://.

Please report new issues to Uzbl's issues page on github