A browser extension that filters pseudo-brand junk out of Amazon. Buy from real, established brands, even when that means paying more.

Amazon is flooded with trademark-squat "brands" (SZHLUX, HORUSDY, LATTOOK, DOZAWA...): random strings registered at the USPTO purely to unlock Amazon Brand Registry, selling commodity goods with no company, no warranty, and no reputation behind them. Knockoff detects those listings and hides, dims, or labels them, right in the search results.

Add to Chrome from the Chrome Web Store, or Add to Firefox from Firefox Add-ons.

Or run the fully local build straight from this repo:

1. Clone this repo
2. Open chrome://extensions
3. Turn on Developer mode (top right)
4. Click Load unpacked and select the repo folder

Works on every Amazon marketplace, with no server behind it.

Safari requires the extension to be wrapped in a native app. Open safari/Knockoff/Knockoff.xcodeproj in Xcode, run the Knockoff scheme, then enable Knockoff in Safari → Settings → Extensions. For unsigned local builds, first check "Allow unsigned extensions" in Safari's Develop menu.

The Xcode project carries its own copy of the extension files; after editing the extension, run scripts/sync-safari.sh to update it before rebuilding.

Some of the coverage since launch:

• Fast Company
• Gizmodo
• 404 Media
• PC Gamer
• Yahoo
• Lifehacker

Everything runs locally in a content script. No accounts, no tracking, no network requests of any kind. Each product tile's brand is resolved through this pipeline (first match wins):

Unknown brands are scored on the linguistic signature of trademark-squat names: ALL-CAPS 5–9 character strings, vanishing vowel ratios, unpronounceable consonant runs, un-English letter pairs, non-Latin characters, random iNternal caPitalization. High scores are flagged, mid scores suspect. The known-brands list always vetoes the heuristics: plenty of real brands (ASICS, RYOBI, HOKA) would otherwise look suspicious. Scoring lives in src/detector.js and is deliberately readable, and easy to tune for your own build.

Filtered items can be hidden (with a floating pill showing the count and a one-click reveal), dimmed (fade + desaturate, restore on hover), or just labeled. Every badge is clickable: trust the brand, block it, show the item once, or report a misclassification.

Product detail pages get a verdict chip next to the brand byline. The page is never hidden out from under you.

This build talks to no server. Every feature that could make a network request is either satisfied from bundled data or turned off:

• Brand lists — the ~5,000 known brands and the community allowlist ship in data/. There is no daily refresh; the bundled snapshot is the whole list.
• DOM config — the selectors the scanner uses live in data/config.js. There is no config push; the bundled copy is authoritative.
• Reports — the one-click "wrong verdict" button opens a prefilled GitHub issue instead of POSTing to an API.

The switches for all of this are the three constants at the top of src/content.js — BRANDS_URL, CONFIG_URL, and REPORT_ENDPOINT — which ship blank. Point them at your own host to re-enable on-demand list refresh, config pushes, and structured reports. (The server itself is not part of this repo.)

The badge menu has one-click reporting ("this is junk" / "this is a real brand"). Because this snapshot ships with no report endpoint configured, a report opens a prefilled GitHub issue rather than posting anywhere. Wire up your own endpoint (see Self-contained by default) to collect them as structured POSTs instead — brand, verdict, ASIN, marketplace, and extension version, no PII.

There is no build step — the extension is plain JavaScript, loadable directly from the repo — so the lists are easy to tune for your own copy. A real brand getting filtered goes in data/known-brands.js; a pseudo-brand getting through goes in data/flagged-brands.js; the full rundown is in CONTRIBUTING.md.

Because this repository is a frozen snapshot, pull requests here won't ship to the published extension — but your edits take effect immediately in a local build.

manifest.json             MV3 manifest
data/known-brands.js      curated established brands (edit this one!)
data/chinese-major.js     established Chinese-owned brands (toggleable)
data/flagged-brands.js    seed blocklist of notorious pseudo-brands
data/generic-words.js     common title words, for unbranded detection
data/community-brands.js  bundled community allowlist snapshot (generated, don't edit)
src/detector.js           detection engine (pure logic, no DOM)
src/content.js            page scanning, badges, actions, in-page control panel
src/background.js         toolbar button → panel toggle (or options page)
options/                  settings page (rules, allow/blocklist)
safari/                   Xcode wrapper app for Safari (macOS)
store-assets/             Chrome Web Store images + the HTML frames that render them
scripts/                  maintenance scripts

• Mixed-case gibberish ("Geinxurn", "Mulwark") scores below the suspect threshold at standard level; Strict mode catches it. A bundled character bigram model would fix this properly.
• Carousels and a few exotic tile layouts aren't scanned yet (TILE_SELECTORS in src/content.js is the extension point).
• Non-English stores are best-effort. Brand lists and the product-page chip work everywhere, but the name heuristics are English-tuned, so an unlisted local brand can slip through. Non-Latin listings (Japanese, Arabic) are skipped rather than mis-filtered, so nothing breaks on any marketplace.

Research that shaped this design: AmazonBrandFilter (allowlist approach; its MIT-licensed community list seeded Knockoff's own) and The Markup's Amazon Brand Detector. Knockoff's contribution is combining a community allowlist with a heuristic scorer, with the allowlist as veto.

This snapshot is released under FSL-1.1-MIT (each version converts to MIT two years after its release). Knockoff is no longer developed as an open-source project: active work happens in a private repository, and future versions are not published here.