Mastodex

About

Mastodex scans your Twitter/X following, followers, blocked accounts, or list members and searches for matching Mastodon accounts — so you can rebuild your social graph on the fediverse without starting from scratch.

🔍 How it works

1. Sign in with your Mastodon account (any instance).
2. Navigate to your Following, Followers, Blocked, or List Members page on X.
3. Click the Mastodon button in the header (or use the popup).
4. Mastodex scrolls through your list, searches for each person on Mastodon, and shows you the matches.
5. Follow, block, or import users to a list right from the results page.

🧠 Smart matching

Mastodex finds accounts using multiple signals:
- Username matching: compares X handles against Mastodon usernames.
- Display name matching: finds accounts with the same display name.
- Bio detection: if someone has their Mastodon handle in their bio, Mastodex looks them up directly.
- Bio similarity: flags accounts with similar bios for higher confidence matches.

Each match is color-coded so you can see at a glance how it was found.

⚡ Results you can act on

The results page shows every detected Mastodon account with:
- Match type labels (username, display name, bio handle)
- Activity indicators (last post date, inactive warnings)
- One-click follow/block buttons
- Filters to focus on the matches you care about

If a match looks wrong, you can re-search to pick a different Mastodon account, or remove it from the list entirely.

🌐 Works with any Mastodon instance

Mastodex uses standard OAuth to connect to your Mastodon instance — mastodon.social, fosstodon.org, your self-hosted server, or any other instance. It requests only the permissions it needs (read, follow, block, and list management) and never stores your password.

🔒 Privacy-first

- All matching happens through your Mastodon instance's search API, with no external servers involved.
- Your X data is scraped locally from the page DOM and never sent anywhere except to your own Mastodon instance for search queries.
- Host permissions are requested dynamically for your specific instance only.
- No analytics, no tracking, no data collection.

📄 Supports multiple page types

Scan from any of these X pages:
- Your following or followers list
- Any user's following or followers list
- Your blocked accounts
- Members of any list you've created

👤 Profile search

When browsing individual profiles, Mastodex adds a button next to the follow/message buttons. Click it to search for that person on Mastodon without running a full scan.