To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!Close
Welcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.Close
StumbleUpon 4.21 Requires Restart
StumbleUpon is the easiest way to discover new and interesting photos, videos, web pages and more, recommended by a community of experts. Tell us what you are interested in and we recommend page after page of amazing stuff you’d never expect to see.
About this Add-on
StumbleUpon is the easiest way to discover new and interesting stuff from all corners of the world. Simply click the “Stumble!” button, and we’ll recommend page after page of the best stuff on the Internet. We guarantee there is something we have that you have never seen! Share what you find with anyone via email and Facebook. Organize your likes and bookmarks into lists to share with your followers.
Start exploring the remarkable world around you. Get ready to go beyond what you already know into an endless stream of fun.
Do not report problems with StumbleUpon to this page. Submit them here:
The Development Channel lets you test an experimental new version of this add-on before it's released to the general public. Once you install the development version, you will continue to get updates from this channel. To stop receiving development updates, reinstall the default version from the link above.
Caution: Development versions of this add-on have not been reviewed by Mozilla.
- Version 4.20b2: