I built a tool that checks if your ISP is spying on you

The site runs 4 checks directly from your browser in ~5 seconds:

* Header injection — echoes your HTTP headers back through a server-side endpoint to detect UIDH supercookies (Verizon injects these at the network level, visible even in private browsing), AT&T tracking headers, Blue Coat proxy markers, and subscriber IDs

* DNS privacy — checks your resolver's ASN via ipinfo to see if it's your ISP's own DNS (which logs every domain you visit) or a private resolver like 1.1.1.1 / 9.9.9.9

* TLS interception — hits the Cloudflare debug endpoint to detect middlebox fingerprints that indicate your "encrypted" connection is being terminated before it reaches the destination

* Leaderboard — anonymized aggregate scores by ISP, so you can see how your provider compares to others

No sign-up, no install, no IP storage (IPs are hashed with a daily-rotating salt). Tech stack is Next.js + Supabase on Vercel.