X Mate

A tiny Chrome extension that blocks ads on X (twitter.com / x.com) — both promoted posts in the timeline and the sidebar's ad banner.

→ Install from the Chrome Web Store

What it blocks

X ads come in two distinct shapes, and X Mate targets both by matching the same DOM markers X's own client uses internally:

1. Promoted timeline posts. Every ad tweet is wrapped in a data-testid="placementTracking" impression-tracking block. X Mate hides the entire virtualized list cell (data-testid="cellInnerDiv") that contains one, removing the promoted tweet and its tracking pixels together. X reuses that same test id for the wrapper its video player mounts into, so the rules only count a block that sits outside the tweet's <article> — an ordinary video won't vanish when you press play.
2. Sidebar ad banner. The "Who to follow" module is immediately followed by a data-testid="whoToFollowSspAd" block — a real Google Ad Manager (GPT) iframe. X Mate hides it, along with any other div-gpt-ad* / google_ads_iframe* slot or googlesyndication.com / doubleclick.net iframe anywhere else on the page.

Blocking is done with CSS :has() rules (Chrome 105+), so ads are hidden before they ever paint — no flash of promoted content. A lightweight content script counts how many ads were hidden for the popup's stats, and flags the one case CSS can't tell apart on its own: a promoted video, which carries both kinds of placementTracking block.

Install

From the Chrome Web Store — one click, auto-updates.

Or unpacked (dev mode)

1. Clone this repo.
2. Open chrome://extensions.
3. Enable Developer mode (top right).
4. Click Load unpacked and select the x_mate folder.
5. Open x.com — ads are blocked. Click the toolbar icon to toggle blocking on/off or see how many ads have been blocked.

Project structure

manifest.json    Manifest V3 config
content.css      The actual ad-hiding rules
content.js       Sets the on/off state early, counts blocked ads
popup.html/.css/.js   Toolbar popup UI (toggle + counter)
icons/           Extension icons

Why this approach

X's markup is unstable (auto-generated class names change constantly), but data-testid attributes are how X's own frontend tests target these elements, so they're the most stable hooks available from outside the app. If X changes these test ids, the rules in content.css are the only place that needs updating.

Limitations

• Requires a Chromium browser new enough to support CSS :has() (Chrome 105+).
• Only targets the two ad surfaces described above; it is not a general purpose ad/tracker blocker.

License

MIT — see LICENSE.