Observe the observers

Install

One click from the Chrome Web Store, on Chrome or any Chromium browser — Edge, Brave, Arc. It updates itself from there.

Prefer an unpacked build?

Optional — for pinning a specific version, or loading it where there is no store listing yet (Firefox). Chrome does not install extension zip files directly; it loads the unzipped folder.

1. 01Download the Chrome build.
2. 02Unzip the file on your computer.
3. 03Open chrome://extensions and turn on Developer mode.
4. 04Choose Load unpacked and select the unzipped chrome-mv3-prod folder.
5. 05Open or refresh a page, then click the Proof Extension icon to inspect what was observed.

What it shows

• Names who is watching the current tab — 44 known trackers across ad platforms, ad auctions, identity resolution, session replay, and site tooling — grouped by company, with evidence and a confidence level on every claim.
• Shows what you are worth: an estimated dollar value per visit and per year to each company watching, from public revenue disclosures — labeled as estimates, with sources.
• Catches trackers that hide: software running inside the page is detected even when its network request was cached, proxied, or cloaked, and identifier hand-offs between tracking companies are reported as they happen.
• Explains every observation in plain language — what was collected, what it is used for, and why it matters — no jargon, no fear copy, and never the word safe.
• Puts the two actions that matter on every tracker card: opt out of future collection and request deletion of held records, with the time cost and ID requirements shown before you click. Eleven trackers link to opt-out URLs from the companies' own government registry filings.
• Refuses to offer blocking where blocking would break the site — chat widgets, forms, tag delivery — and says so instead of breaking pages.

What it cannot do

This build is not a promise of anonymity. Some exposure is outside the browser’s control:

• Stop the destination server from seeing your IP address or request headers.
• Undo server-side logging or delete records a service already holds.
• Prevent TLS fingerprinting or anything that happens before content scripts run.
• Tell you that you are “safe.” It only reports what it observed.

Roadmap

What is real today, and what is planned. Nothing here is a promise until it ships with evidence behind it.

• ShippedObservation with evidence and confidence, per-tracker blocking with breakage guards, in-page tracker software detection, identifier hand-off (cookie sync) detection, first-party fingerprint reporting, and dynamic script detection.
• ShippedPer-person value: what each watching company earns from you per visit and per year, sourced and estimate-labeled, with a running local ledger.
• ShippedSource-level action on every tracker card: opt out and request deletion, with time cost and ID requirements up front — registry-filed URLs where the company is a registered data broker.
• ShippedIdentity narrowing: the GPU, canvas, fonts, timezone, and screen each page can read, collapsed on-device into how few people you could be — the same entropy model this site uses, run locally with nothing sent.
• ShippedWhere your IP puts you: a MaxMind-backed map pin drawn from one disclosed request, made only at your click — the single time the whole extension touches the network.
• ShippedOne-click install: the Chrome Web Store listing is live for Chrome and Edge. The unpacked build stays available for pinning a version or loading where no store listing exists yet.
• NextBreadth toward Ghostery-scale coverage — driven by what the extension actually observes, not a static list. Unclassified parties seen on real pages are matched to their vendor's own policy documents and added as source-backed records, so the named set grows from evidence.
• NextReal canvas, WebGL, and audio mitigation you can toggle — today those surfaces are read and reported, not yet constrained.
• NextSecurity and privacy-leak indicators: tokens in URLs, referrer leakage, cross-origin form posts, mixed content.
• LaterFirefox Add-ons and Safari listings. The core is browser-agnostic; the adapters differ.
• LaterOpt-in AI explanation of a tab report — off by default, with payload preview and redaction. AI never becomes the evidence or the blocking decision.