Last updated: Oct. 4, 2026

Xnnoying (“the Add-on”) is a Firefox add-on that adds quick block and mute buttons directly on posts on x.com and twitter.com, and keeps a history of your Home feed. This privacy policy describes what data the Add-on accesses, how it is used and how it is protected.


The Add-on accesses the following data while you use x.com or twitter.com:

• Authentication cookie: The Add-on reads your existing session cookie (ct0 CSRF token) from the browser to authenticate block and mute requests with X’s API on your behalf.
• Website content: The Add-on reads usernames (screen names) from the posts displayed on the page to identify which account to block or mute when you click a button.
• Home history: On your Home timeline, the Add-on records the ID, author and a short text snippet of posts you scroll past, plus the furthest post you reached, so you can find your place again after X reloads the feed.
• Home feed data: To restore a feed X replaced, the Add-on keeps a copy of the Home feed data X’s own servers send to your browser.

Accessed data is used only to perform the block or mute action you initiate and to keep and restore your Home history. Specifically:

• Your CSRF token is included in the request headers sent to X’s own API endpoints (blocks/create and mutes/users/create) so the action is performed under your authenticated session.
• The screen name is included in the request body sent to those same X API endpoints.

Data for block and mute is used transiently at the moment you click a button and is not stored.

Home history is stored only in Firefox’s local add-on storage (storage.local) on this device. It is limited to the 10 most recent feeds of up to 300 posts each, older entries are discarded automatically, and it is removed when you remove the Add-on. It is never sent anywhere.

Home feed data is held only in the tab’s memory (the last 5 feeds, about 40 MB at most) and is discarded when the tab is closed or reloaded. When you choose to restore a feed, that feed is placed in the tab’s session storage, and the other saved feeds in Firefox’s IndexedDB storage for x.com, just long enough to reload the page, then removed. It is never sent anywhere.


The Add-on does not transmit any data to the developer or to any third-party server. All network requests are sent exclusively to X’s own API on the same domain you are already browsing (x.com). No data is sold, shared or transferred to any third party, and none is used for advertising or any purpose unrelated to the Add-on’s features.


All requests to X’s API are made over HTTPS. Apart from Home history in local add-on storage, and saved feeds held briefly in session storage and IndexedDB during a restore, the Add-on does not store any user data locally or remotely.


The Add-on requires access to x.com and twitter.com, and the storage permission to keep Home history on your device. It uses no other permissions and has no background scripts, analytics or tracking of any kind.


If this policy is updated, the revised version will be posted here with an updated date.


If you have questions about this privacy policy, you can reach the developer through the support section of this add-on’s listing on Firefox Add-ons, or at https://xnnoying.com.