You aren't required to list or distribute your add-on through addons.mozilla.org (AMO); you can distribute it yourself. However, before distributing your add-on yourself, here are some things you should consider:
AMO is a very popular distribution platform, with millions of monthly visitors and installations. It's integrated into the Firefox Add-ons Manager, allowing for easy installation of add-ons published on AMO.
When an add-on is listed on AMO, Firefox automatically updates installed copies when a new version is listed on AMO. To enable Firefox to automatically update self-distributed add-ons, you need to include the URL where Firefox can find updates in the add-on manifest's update_url key. If the add-on does not have an update URL to check, Firefox will check AMO for a listed update. If a listed update with a higher version number is available, Firefox will distribute that version to users who have installed the self-distributed file.
For more information on how to submit an add-on for distribution on AMO or self-distribution, see Submitting an add-on.
When you choose to distribute an add-on yourself, they can be installed using the following methods:
- Web download—make your extension available on a suitable web accessible server and when the user downloads the signed add-on file Firefox will install it.
- Installing add-on from file—enables a user to install an add-on using an
.xpifile saved on their computer.
- Add-ons for use with a desktop app—starting with Firefox 74, it is no longer be possible to have an extension be automatically installed as part of another application install. See the Add-ons Blog for more information.
- Add-ons in an enterprise environment—this page discusses the use of signed compared to unsigned extensions, installation options, the Firefox settings affecting installation, and including add-ons with a custom Firefox install package.