ZeroSync's Header Chain Verifier: Instant Bitcoin Header Chain Verification

"This is a simple demo of a chain state proof. It runs the miniSTARK verifier in WebAssembly to verify a recursive proof of Bitcoin's header chain in your browser."

https://www.nobsbitcoin.com/zerosyncs-header-chain-verifier-instant-bitcoin-header-chain-verification-in-your-browser/