Install Mozilla Archive Format

For Firefox and SeaMonkey.

This link downloads the most recent version available at the Mozilla Add-ons website. This version is updated less frequently, tested more extensively, and fully translated in several languages.

Try Mozilla Archive Format 4.0b2

This preview improves compatibility over previous versions.

This link downloads the add-on from this website, where new versions are published as soon as they are available. If you download from this link, you will get new features sooner, although at first they will be available only in English.


Mozilla Archive Format, at the time of each release, is tested and verified with the most recent browser versions available in the following release channels:

  • Firefox Beta
  • Firefox Release
  • SeaMonkey Beta
  • SeaMonkey Release

Testing is done under Windows XP, but the add-on is expected to work on all the platforms supported by the browser. Note that the add-on is not expected to be compatible with the Nightly channel, though partial compatibility might be implemented for the Aurora channel.

File format compatibility

MAFF files are standard ZIP files that can be extracted and read with any browser and operating system. For an overview of browser support for the MHTML format, see the summary on Wikipedia.

Add-on compatibility

Mozilla Archive Format is also written to be compatible with the largest number of other browser add-ons, with few known exceptions for older or unmaintained add-ons. In addition, Mozilla Archive Format is routinely tested together with other compatible extensions on the latest version of Firefox. If you find out a case of incompatibility, you can report it through the feedback page.

License and copyright

The Mozilla Archive Format extension for Firefox has been created by Christopher Ottley and is now actively developed by Paolo Amadini. Mozilla Archive Format also includes code from the Save Complete extension, created by Stephen Augenstein. The latest version of the add-on is available under a MPL 1.1+, GPL 2.0+, LGPL 2.1+ disjunctive tri-license. Previous versions of the add-on and individual source files may be available under different Open Source licenses. See the source code for more information.

What's new in the latest version?

MAF 4.0b2 has the following user-visible improvements over MAF 3.1.0:

  • When multi-process Firefox is enabled, compatibility information is displayed in English in the main pane of the options dialog, and the dialog is shown automatically the first time this condition is detected.
  • Partial compatibility with multi-process Firefox:
    • Full support for displaying the contents of web archives.
    • The notification bar with information about the original save date and location is not displayed when multi-process Firefox is enabled.
    • Web archives cannot be created when multi-process Firefox is enabled, however it is now possible to use the browser's standard save system to save complete web pages in multiple files, without disabling the add-on first.
  • Several features have been removed or redesigned in preparation for full compatibility with multi-process Firefox:
    • Taking an exact snapshot of the page is now required to create web archives, and the browser's standard save system can only be used to save complete web pages in multiple files. All the generated MHTML files are now fully compatible with other browsers, since the option to create partially compatible archives using the browser's standard save system is not available anymore.
    • The separate Archives dialog has been removed.
    • The integrated Save Complete component has been removed.
    • The existing integration with the page context menu, the Tools menu, and the application menu of older versions of Firefox has been removed in favor of the integration with the customizable menu button.
    • The preference to use the page title instead of the default suggested file name in the "Save As" dialog has been removed since this is now the default naming strategy in Firefox.

What was new in the previous version?

Known issues

MAF 4.0b2 has the following known issues:

  • In order to open MHTML files when the IE Tab extension is installed, the filter /^file:\/\/\/.*\.(mht|mhtml)$/ must be disabled from the IE Tab options.
  • The Download Sort extension has a known incompatibility with MAF. The conflict cannot be resolved without proper modifications to both extensions, and Download Sort is not actively maintained at this time.
  • When saving multiple tabs in an archive, the save operation fails if the tabs are closed before the operation is completed.
  • When saving a page in an archive fails, retrying the download from the Downloads window does not achieve the expected result.
  • Opening very long documents contained inside MHTML files may cause the browser to stop responding temporarily.

Previous versions and source code

You can download all the previous versions of MAF from the project page. The changelog for all the old versions is also available. Source code for the released versions can be found in the XPI installation files, and can be read using any ZIP extractor. Source code for the development versions of MAF can be accessed from the source code page.