Filtro Privacy Policy

Last updated October 29, 2026

Filtro is a browser extension that hides posts on X (x.com and twitter.com) that match your rules or come from accounts you block. It works inside your browser. It has no user accounts, shows no ads, and does not sell or share your data. It only contacts its server for the features listed below, and it only contacts X when you click a button asking it to.

What stays in your browser

Filtro reads the posts X shows you, in your browser, to decide which ones to hide. Post content is never sent anywhere. These are kept in your browser's extension storage and never leave it:

• Your settings: rules, blocked accounts, the "Always show" list and your preferences.
• Local stats: how many posts were checked, hidden and shown again; how often each rule matched; emojis seen in display names of posts; and errors.
• Missed posts: when you right-click a post and choose "Filtro: block this account", the handle, display name, text and bio of that post's author are saved so you can see which posts your rules missed.
• Bios: the bio and location of accounts that X already shows you (profiles you open, hover cards, account lists), so rules can match them. Kept for up to 5,000 accounts and dropped 30 days after last seen.
• Follows: which accounts X shows you follow (on profiles you open, hover cards and account lists), so your rules never hide them. Kept for up to 10,000 accounts.
• Account and rule lists: the private edit keys of lists you publish, the lists you subscribed to, and which lists you added or reported.

Removing the extension deletes all of this. The settings page can also clear stats and saved bios, and export or reset your settings.

What is sent to the Filtro server

The server is a Cloudflare Worker run by Filtro's developer. Requests carry no cookies, and the server does not store IP addresses or any identifier for your browser or device.

• Selector updates: about every 6 hours, Filtro asks the server whether X changed its page layout. The request contains nothing about you.
• List pages: each published list also has a public web page on this server, to share it. On those pages only, Filtro adds an "Add to Filtro" button, which opens the list in Filtro's settings. Nothing is added until you click Add and Save there, and the page learns nothing about you from the extension.
• Account and rule lists: when you browse lists, your search text. When you publish or edit a list, the name, description and accounts or rules you entered, including accounts you add to your own list from X's menu. Published lists are public: anyone using Filtro can see them. When you add or subscribe to a list, a counter of how many browsers added it goes up by one. If you subscribe to lists, Filtro fetches each one about once a day to pick up changes; those requests contain only the list's id. When you report a list, the reason and any details you write.
• Anonymous usage stats, only if you turn them on (Settings, "Anonymous sharing"; off by default): once a day, daily totals (posts checked, hidden, shown again, errors and similar counts), each of your blocked accounts once with how it was added and whether its posts appeared, which settings are on, and the extension version. This never includes your X account, post text, display names, your rules, or any identifier for your browser. The settings page shows exactly what the next report contains.

Cloudflare, which hosts the server, processes IP addresses in order to deliver requests, as for any website (see Cloudflare's privacy policy). Request logging is turned off for this server.

What is sent to X

Filtro never mutes or blocks anyone on X by itself. When you click "Mute on X" or "Block on X" on a hidden post, or "Retry failed" in the settings, Filtro sends that one mute or block request from your browser to x.com, using the login already open in that tab, the same request X sends when you use its own menu. Filtro does not read, store or send your X password, and does not send your X session anywhere else.

How long data is kept

• Published lists stay until you delete them (Settings, "My lists") or the developer removes them for spam or abuse.
• Reports are kept until the list is reviewed or deleted.
• Anonymous usage stats are stored only as running totals, not as individual reports.

Sharing

Filtro does not sell, rent or share data with anyone, does not use it for advertising, and does not use it to decide anyone's credit or eligibility for anything. The only third party involved is Cloudflare, as the server's host.

The use of information received by Filtro complies with the Chrome Web Store User Data Policy, including the Limited Use requirements.

Children

Filtro is not directed at children under 13.

Changes

If this policy changes, the new version will be posted at this address with a new date.

Contact

Questions about privacy: use the support link on Filtro's Chrome Web Store page.