Provably Fair Verifier
Independently verify that your crypto casino game was fair. Paste your seeds, pick your game — we recalculate every result using SHA-256 and HMAC-SHA256.
Step 1: Hash Verification
Computed SHA-256
--Committed Hash
--Step 2: Result Verification
Complete Step 1 first — verify the server seed hash before computing results.
Batch Verification — Verify Entire Session
Complete Step 1 first — verify the server seed hash before running batch verification.
Seed Explorer
Enter seeds above and verify the hash to unlock the Seed Explorer.
Strategy Tester on Seed
Enter seeds above and verify the hash to unlock the Strategy Tester.
How Provably Fair Works
Provably fair is a cryptographic system used by crypto casinos to let players independently verify that game results were not manipulated.
1. Casino Commits
Before you play, the casino generates a server seed and gives you its SHA-256 hash. This hash locks in every game result — the casino cannot change it after the fact.
2. You Play
Each bet combines three inputs: the server seed, your client seed, and a nonce (bet number). HMAC-SHA256 processes these into a deterministic result — the same inputs always produce the same output.
3. You Verify
After your session, the casino reveals the unhashed server seed. You check: does SHA-256 of the revealed seed match the hash you received before playing? Then recalculate each bet result independently.
This tool verifies cryptographic fairness — it does not guarantee positive outcomes or winning strategies. Gambling involves risk. If you or someone you know has a gambling problem, call 1-800-522-4700 (NCPG Helpline).