SupafastBlock
Block ads. Even promoted posts.
Chrome extension that blocks ads, trackers, cookie banners and promoted posts. 84k+ AdGuard rules, Element Zapper, no data collection.
Overview
SupafastBlock is a Manifest V3 Chrome extension that blocks ads and trackers via 84,000+ AdGuard filter rules. It goes beyond network blocking: content scripts detect and hide promoted and sponsored posts on X (Twitter), Reddit, LinkedIn, and VK using MutationObserver.
The Element Zapper lets you click any element on any page to hide it permanently, with rules persisted per hostname. A per-site allowlist lets you disable blocking for specific domains in one tap, synced across your Chrome devices.
Built without any remote code, backend, or data collection. All filter rules ship inside the extension package.
The problem
Ad blockers based on older Manifest V2 are being phased out by Chrome. Most MV3 alternatives sacrifice filtering power for compliance. At the same time, social networks flood feeds with promoted content that network-level blocking cannot catch.
What we built
- 84,000+ AdGuard filter rules via declarativeNetRequest (worldwide + Russian)
- Blocks promoted and sponsored posts on X, Reddit, LinkedIn and VK
- Cookie banner blocking with one toggle (optional annoyances filter)
- Element Zapper: click any element to hide it permanently per hostname
- Per-site allowlist synced across Chrome devices
- Privacy report showing active tracker companies per tab
- Statistics: blocked count today, 7 days, all time with traffic and time saved
- No data collection, no remote code, no backend - privacy by design
Tech stack
Extension
Blocking
Content Scripts
Under the hood
84k rules via DNR static rulesets
Six AdGuard rulesets ship as pre-compiled DNR JSON inside the extension: Base filter (72k rules), Russian filter (6k), URL Tracking filter (875), and three optional annoyances rulesets. Chrome enables them via declarativeNetRequest.updateEnabledRulesets - no runtime filter parsing, sub-5ms build time.
Content scripts: MutationObserver + two-layer detection
Site-specific detectors (X, Reddit, LinkedIn, VK) and global detectors (Yandex Direct, Adfox) run in parallel via MutationObserver with 100ms debounce. Elements are hidden via style.setProperty with important flag and tagged data-supafastblock-hidden. Selector generation prefers #id, falls back to stable class path up to 5 ancestors deep.
