Mastodex door Miguel Piedrafita

Mastodex finds your Twitter/X connections on Mastodon. Scan your following, followers, blocked accounts, or list members — Mastodex searches for matching Mastodon accounts and lets you follow or block them with one click, right from the results page.

How it works

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

Smart matching

Mastodex uses multiple signals to find the right accounts:

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

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

Results you can act on

• Match type labels and activity indicators
• One-click follow and block buttons
• Filters to focus on the matches you care about
• Re-search to swap a wrong match for the right account

Works with any instance

mastodon.social, fosstodon.org, your self-hosted server -- any Mastodon-compatible instance. Mastodex uses standard OAuth and only requests the permissions it needs.

Privacy-first

• No external servers: all searches go through your own Mastodon instance
• X data is scraped locally from the page and never stored or sent elsewhere
• Host permissions are requested dynamically, scoped to your instance only
• No analytics, no tracking, no data collection

Profile search

When browsing individual X profiles, Mastodex adds a button to search for that person on Mastodon without running a full scan.