Browser verifier for HMAC-SHA256 game results

Paste a revealed server seed, your client seed and the nonce. Everything is computed in your browser with the Web Crypto API; nothing is sent anywhere.

What the tool computes

• Commitment: SHA-256 of the server seed, compared with the hash you were shown.
• HMAC: HMAC-SHA256 keyed with the server seed over clientSeed:nonce plus the optional game tag.
• Float: the first 4 bytes as an unsigned integer divided by 2³².
• Common mappings: dice roll (float × 100), coin flip (heads below 0.5), rock–paper–scissors (floor(float × 3)), limbo result at a 3% edge, crash point at a 4% edge.

Mappings differ between sites. Always compare with the game's published rules; the defaults reproduce the public test vector used in our dice tutorial.