BlockTube not working? What to check

Details below are from BlockTube’s GitHub page and source code as of November 6, 2026. Its Firefox version, 0.4.8, was last updated on February 20, 2026.

1. Is it switched on?

BlockTube’s toolbar popup has an Off switch and an Options button. A switch flipped by accident is the quickest thing to rule out. After changing it, or after installing or updating BlockTube, reload the YouTube tab: an extension’s filters reach a page only when the page loads.

2. How filters are written

This is also the short version of how to use BlockTube. Its settings page has separate lists for Video title, Channel name, Video ID, Channel ID and Comment content. Each line is one filter. From the source code:

• A plain word matches a whole word, in any case. cat catches “Cat videos” but not “category”.
• A line written as /pattern/flags is a regular expression. Without the i flag it’s case-sensitive, so /prank/ misses “PRANK”. Use /prank/i.
• IDs must be complete and exact. A video ID or channel ID matches only in full, so a stray space or a missing character means no match.
• Lines starting with // are ignored. They’re treated as notes, so a filter that starts with them does nothing.

Check that each filter sits in the right list, too. A channel’s name in the Video title list only matches videos that mention it in the title.

3. Channel name or channel ID

BlockTube’s FAQ explains that channel names aren’t unique and can change, while a channel ID never changes. If a channel you blocked by name is back, it may have renamed itself. Block it by ID instead. The ID starts with UC and appears in addresses of the form youtube.com/channel/UC….

The easier route skips IDs entirely: BlockTube adds Block Channel and Block Video to the ⋮ menu next to videos on YouTube, and adds the entry to your lists for you.

4. Private windows and other browsers

• Chrome and Edge keep extensions off in private windows until you allow them: open the extensions page, choose Details under BlockTube, and turn on Allow in Incognito (InPrivate in Edge).
• Firefox has a Run in Private Windows setting on the add-on’s page in Add-ons and themes.
• Another browser or computer starts empty. BlockTube’s settings stay in the browser they were made in; sync is on the project’s list of future work. Use Export and Import to copy them across.

5. Options that let things through

A few of BlockTube’s settings switch part of the blocking off on purpose. Look for the ones whose names begin with “Disable”, such as Disable direct access blocking and Disable blocking on watch history page, and untick any you didn’t mean to set. If you use Advanced blocking, which runs a JavaScript function you write, an error in it is worth ruling out too.

6. YouTube changed something

BlockTube filters YouTube’s data before the page is drawn. That’s why blocked videos don’t flash on screen, and also why a change in how YouTube sends its data can leave a filter matching nothing. If everything above checks out:

• Search the project’s GitHub issues for the same symptom. If it’s new, report it with your browser, BlockTube version and a sample video.
• Check you have the latest version from the Chrome Web Store or Firefox Add-ons.

The project had more than 480 open issues in November 2026, so a fix can take a while.

7. On a phone

No extension works inside the YouTube app. BlockTube does support YouTube’s mobile website in Firefox for Android, where add-ons are available.

If you’re ready for something simpler

FeedCut covers the everyday part of BlockTube’s job with a Block channel button on YouTube itself, a list with names instead of IDs, and plain words instead of patterns. It imports a BlockTube export: channels and plain words come across, and any regular expressions it skips are listed so you can turn them into words. The BlockTube alternative page compares the two honestly, including what BlockTube does better.

Questions

Updated November 6, 2026