ROULETTE PROVABLY FAIR VERIFIER
Recompute the exact winning pocket of any provably-fair Roulette spin from your revealed seeds and nonce.
This page is pre-set to Roulette. All presets use the same open-source scheme: HMAC-SHA256(server seed, "clientSeed:nonce:cursor"). Stake and Shuffle are confirmed byte-for-byte; other casinos may differ — see the full verifier.
Calculation Breakdown
Provably-fair Roulette (the in-house, non-live version) spins a single European wheel with pockets 0–36. The winning pocket is derived from your seed pair, so each spin can be recomputed and verified. Paste your revealed seeds below to check any spin. (Live-dealer roulette uses a real wheel and camera, so it cannot be verified this way.)
HOW ROULETTE SPINS ARE CALCULATED
European provably-fair Roulette maps a single random float onto 37 pockets:
- Take the first float in [0,1) from
HMAC-SHA256(serverSeed, "clientSeed:nonce:0"). - Winning pocket =
floor(float × 37)→ a number from 0 to 36.
Worked example — server seed some server seed, client seed some client seed, nonce 1 gives float 0.59192619 → pocket 21 (red).
WHY VERIFY ROULETTE?
Provably fair only protects you if you actually check it. Verifying a Roulette round proves the result was computed from the server seed the casino committed to before your bet, combined with the client seed you chose — so the operator could not have altered the outcome after seeing your wager. Spot-checking even a handful of rounds keeps the system honest and removes any doubt during a losing streak.
Want the full picture? The all-games provably fair verifier handles Crash, Dice, Limbo, Roulette, Mines, Plinko and Keno in one place, and our guide on what provably fair gambling is explains the cryptography from the ground up.
Related Resources
Play Roulette: Stake Roulette
Strategy: Crypto Roulette Strategy
Calculate the odds: Roulette Calculator · Plinko Calculator · Keno Calculator
Compare operators: Best Provably Fair Casinos 2026