Check a provably fair round without trusting the casino's own verifier. Everything runs in your browser with the Web Crypto API; seeds never leave your device.
SHA-256 of the server seed-
Dice roll (0.00 to 100.00)-
Limbo result-
First 8 random floats-
What this checks
- Hash check (any casino). Before you play, the casino shows a SHA-256 hash of its secret server seed. After you rotate the seed, it reveals the seed itself. If the hash of the revealed seed matches what you saw earlier, the casino could not have changed the seed while you played.
- Dice and limbo results. Computed with the method Stake publishes for its originals: HMAC-SHA256 keyed with the server seed over client seed:nonce:round, turned into numbers between 0 and 1 four bytes at a time. Dice = floor(float × 10001) ÷ 100. Limbo = 0.99 ÷ float, rounded down to two decimals, minimum 1.00.
How to use it with your bets
- In the casino's fairness settings, note the hashed server seed and your client seed. You can set your own client seed.
- Play. Each bet uses the next nonce (0, 1, 2…).
- Rotate the seed pair. The old server seed is now revealed.
- Paste the values here. The hash should match, and the dice or limbo result for each nonce should equal what the casino showed.
Other casinos and other games (crash, plinko, mines, cards) use their own formulas on top of the same seeds. The hash check above still works for them; for game results, compare with the formula on that casino's fairness page.
The idea behind all this, step by step: how provably fair works.
Updated