Fission combines address bar and progress bar - Safari style, as did Fusion:

Screenshot of Fission filling the address bar during page load


Fission 1.0.9 [released 2009-05-08]

This release works for Firefox 3.0, 3.5 and 3.6 as well as Flock 2.5 (unsupported).

Contact / Feedback

Please post to the official forum thread for feedback, questions and bug reports.

Before reporting any bugs, please read about debugging Firefox extensions first. And for bugs with the default theme, please go through these steps as well. Thanks.

Note: Some themes might break when you install Fission. If that happens for you, please rather contact your theme's author and ask him/her to adapt the theme for Fission (have a look at this post for what modifications might be needed). I only use the default theme and won't be able to help you.


Fission can be minimally styled through its Options dialog and more extensively through userChrome.css:

/* Different background color and some margin (Fusion-style only) */
#urlbar[fission="fusion"] > #statusbar-icon > .progress-bar {
   background-color: #D2BDB6 !important;
   margin: 2px !important;
/* Different text color while the progress bar is shown */
#urlbar[fission="fusion"][progress]:not([progress="0"]):not([progress="100"]) {
   color: #000000 !important;
/* Different text color for linkified URLs */
#urlbar[fission-link] .textbox-input-box { color: blue !important; }

See for more complex Fission specific styles.

Related code snippets

To get an even better experience when hiding the status bar, you could additionally try adding the following code snippets to your userChrome.js:


Screenshot of Fission's options dialog


Current: Version 1.0.9
Fixed two issues with the smoother progress bar
Version 1.0.8
The progress bar advances more smoothly
Version 1.0.6
Added Ukrainian, Indonesian, Turkish, Vietnamese and Hebrew locales (thanks to the translators over at BabelZilla)
Minor fix for Firefox 3.5's default Mac theme
Version 1.0.5
Minor UI polish: Progress bar is always updated when changing tabs, connection status only displayed in one place.
Version 1.0.3
Fission sometimes failed to work (regression in version 1.0.2)
Version 1.0.2
Dropped support for Firefox 2.0 (use Fission 1.0 instead)
Version 1.0.1
Minor update for the latest Firefox 3.1 nightlies
Added a Romanian locale
Version 1.0
Two theme tweaks for Firefox 3.0

Version 0.9.7
Minor update for Firefox 3.0 (RC1)
Version 0.9.6
Images used for the progress bar are now vertically centered
Version 0.9.5
Fixed missing Mac theme support for Firefox 3.0 Beta 4
Version 0.9.4
Updated to the latest Firefox 3.0 Beta 4 nightlies (including a tentative fix for the new Mac theme)
Added a Norwegian locale
Version 0.9.3
New icon (thanks to Savaden)
Update for Firefox 3.0 Beta 3 (still incompatible with the new Mac theme)
Version 0.9.2
Fixed two detail issues
Version 0.9.1
Added compatibility information for Flock 1.0 and Netscape Navigator 9.0
Made the locales added in version 0.8.9 actually work
Version 0.9
Update for

Version 0.8.12
Connection status and mouse-over link are now hidden when the address bar is focused
Version 0.8.11
Added the hidden pref extensions.fission.enableFocusHack for testers
Version 0.8.10
Transparent images now let the address bar background shine through
Updated for Firefox 3.0 Beta 1
Version 0.8.9
Added Belarusian, Hungarian and Greek locales (thanks to the translators over at BabelZilla)
Secured extension update process (for Firefox 3.0 Alpha 8 and later)
Version 0.8.8
Added Thai, Korean, Serbian, Polish, Swedish and Czech locales
Minor bug fix (mainly: mouse-over links removed from the status bar; and the address bar should no longer grow when the connection status is displayed (Pinstripe only))
Version 0.8.7
"Done" is never displayed as connection status
Added Finnish, Catalan and Persian locales
Minor bug fix (most notably: connection status text was mis-aligned)
Version 0.8.6
Added Japanese, Chinese (traditional), Slovak and Arabic locales
Version 0.8.5
Changed the link target icon from MediaWiki style arrow to phpBB 2 style arrow
Bug fix: Fission occasionally wasn't correctly initialized (since 0.8.4)
Version 0.8.4
Added an icon to indicate linkified addresses (see this post for how to disable it)
Added Russian, Chinese (simplified), Portuguese, Spanish, French, Italian, Danish and Dutch locales
Bug fix: displaying the connection status could break the [Tab] key
Version 0.8.2
New Reset button in the Options dialog
Bug fix: the Options dialog was empty with browser.preferences.animateFadeIn set
Version 0.8
Added a Settings dialog

Version 0.7.5
Minor bug fix
Version 0.7.4
New pref extensions.fission.linkify: displays link urls in the address bar
Bug fix: address bar lost focus in new windows
Version 0.7.2
More sensible default color (#B6BDD2)
The color can be changed through about:config
Version 0.7
Connection status can now also be displayed in the address bar (extensions.fission.textify)

Version 0.6
Themes can now easily recognize Fission
Version 0.5
Minor bug fix
Version 0.4
Added a hidden preference to enable the Icon-style progress bar
Bug fix: the progress bar was lost when customizing the toolbars
Version 0.3
Improved compatibility with some themes
Version 0.2
Replaced the icon-style progress bar with a Fusion-style one
Version 0.1
Initial release 2006-01-20
Fission's icon
Logo of zeniko's webcreations