What Is Provably Fair Gambling?
Provably fair is a cryptographic system that allows players to independently verify that a casino game result was not manipulated. Before any bets are placed, the casino commits to a server seed by publishing its SHA-256 hash. The player sets their own client seed, giving them influence over the random number generation.
After the player rotates their seeds, the unhashed server seed is revealed. Using the server seed, client seed, and nonce (bet number), anyone can recalculate the exact outcome of every bet using the HMAC_SHA256 algorithm. If the calculated result matches the actual result, the game was provably fair.
Why Use an Independent Verifier?
While Stake.com provides their own verification tool, using an independent third-party verifier like ours adds an extra layer of trust. Our tool runs entirely in your browser — no seeds are ever sent to our servers or any third party. The source code implements the exact same HMAC_SHA256 algorithm published by Stake, so you can verify your results with complete confidence and privacy.
Supported Games
HMAC → uint32 → max(1, (2^32/(int+1)) * 0.99)
HMAC → float → floor(float * 10001) / 100
Same as Crash (different UI)
N floats → binary path (L/R per row)
24 floats → Fisher-Yates mine placement
Duel.com: 0% House Edge + Provably Fair
Most provably fair casinos have a 1-4% house edge. Duel.com is the only platform we've tested that runs original games at 0% house edge (100% RTP). Crash, Dice, Plinko, Mines, Blackjack, and Keno — all provably fair AND zero edge.
| Casino | Crash Edge | Dice Edge | Provably Fair |
|---|---|---|---|
| Duel.com | 0% | 0% | Yes |
| Stake.com | 1% | 1% | Yes |
| BC.Game | 1% | 1% | Yes |
| Roobet | ~4% | ~4% | Yes |
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Important: Provably fair proves that game results were not manipulated after the server seed was committed. It does not change the house edge or guarantee profits. The house always has a mathematical advantage. Please gamble responsibly.