Mass Block Twitter vs Twitter Blocker vs Twitter Filter

If you've used Mass Block Twitter (MBT), you might have noticed two newer extensions from me: Twitter Blocker and Twitter Filter. This post explains why MBT was split into two separate tools and which one you should use.

What Mass Block Twitter did

MBT was my first attempt at solving the spam problem on Twitter/X. It started as a simple bulk blocking tool, then grew to include rule-based filtering, dynamic blocking, and more. Over time, it became a single extension doing two very different things:

1. Batch blocking — import a list of users and block them all
2. Rule filtering — hide or block tweets matching custom conditions in your timeline

Both features work, but packing them into one extension created problems. The architecture was designed early on without planning for cross-platform support, making it very difficult to update. It couldn't support iOS Safari at all, and adding new features meant risking breakage in unrelated parts.

Why split into two extensions

Instead of continuing to patch MBT, I rebuilt each feature as a standalone extension with a modern architecture:

• Twitter Blocker extracts and improves the batch blocking feature
• Twitter Filter extracts and improves the rule filtering feature

The biggest benefit of the new architecture is full cross-platform support. Twitter Blocker is already on the App Store for iOS Safari, and Twitter Filter supports Safari as well. Both also work on Chrome, Edge, and Firefox.

Twitter Blocker: batch blocking done right

Twitter Blocker focuses on one thing: blocking (or muting) a list of users reliably.

What's improved over MBT:

• True background processing — operations run in a service worker. You don't need to keep a tab open. Just have the browser running.
• Automatic rate limit handling — Twitter's blocking API allows roughly 500 blocks per day safely. The extension tracks this locally and auto-waits when limits are reached, then resumes. No force logouts.
• CSV import — import user lists from Twitter Exporter or any tool that outputs id and screen_name columns.
• Cross-platform — works on Chrome, Edge, Firefox, and iOS Safari.

If you need to block fewer than ~3,500 accounts, Twitter Blocker can handle it automatically in the background over a week or so. For larger numbers, you may want to combine it with dynamic blocking via Twitter Filter (see below).

Twitter Filter: smarter timeline filtering

Twitter Filter focuses on real-time timeline cleanup using expression-based rules.

What's improved over MBT:

• More powerful rule expressions — access user fields (followers, account age, bio, verification status) and tweet fields (text, media, links). Combine them with contains, matches (regex), days_since(), and logical operators.
• Cross-device rule subscription — sync your rules across browsers and devices.
• Three actions per rule — mark (yellow border), hide (remove from timeline), or block (send a block request with configurable delay and undo).
• Dynamic blocking — for large-scale blocking where the batch approach would take too long, you can write a rule that blocks matching accounts as they appear in your timeline. This avoids hitting rate limits because it only blocks accounts you actually encounter.

Twitter Filter is free and works on Chrome, Edge, Firefox, and Safari.

Which should you use?

Use Twitter Blocker if:

• You have a specific list of accounts to block (CSV from Twitter Exporter, shared block lists, etc.)
• You want a set-and-forget background process
• You need iOS Safari support for blocking

Use Twitter Filter if:

• You want to clean up your timeline in real time based on rules (spam, bots, crypto promotion, etc.)
• You need dynamic blocking — blocking accounts as they appear rather than from a pre-made list
• You want to hide or mark tweets without actually blocking the account

Use both together for maximum control: Twitter Filter handles your day-to-day timeline cleanup, while Twitter Blocker processes bulk lists when you need to block a large batch of known accounts.

Migrating from Mass Block Twitter

MBT continues to work, but it won't receive major updates due to its architecture limitations. If you're currently using MBT, here's the migration path:

• For batch blocking → install Twitter Blocker
• For rule-based filtering → install Twitter Filter

If you previously paid for Mass Block Twitter, contact support with your receipt and I'll provide a 100% discount code for Twitter Blocker.