Fairness tools
Provably fair verifier
A published hash proves nothing if nobody ever checks it. Paste the revealed seeds from a completed round and reproduce the result yourself.
The HMAC hash above is computed entirely in your browser and is exactly reproducible — the self-test confirms our engine matches the published RFC 4231 reference vector. The Dice resultuses Stake's documented byte-to-float mapping (floor(float × 10001) ÷ 100). Other games (Limbo, Crash, Mines, Plinko) and some operators use different result mappings or a different nonce/cursor order — always confirm against your operator's published method. Full per-game decoding for more games is on the way.
How verification works
- Before the bet, the operator generates a secret server seed and shows you only its SHA-256 hash. That hash is a commitment: it cannot be reversed to reveal the seed, but the seed can later be checked against it.
- You contribute a client seed, which the operator cannot predict. Because your input is mixed in, the operator cannot know the outcome in advance even though it chose its own seed.
- Each bet adds a nonce, an incrementing counter, so the same pair of seeds produces a different result every round.
- Afterwards the server seed is revealed. Hash it and compare with the original commitment; combine the three values with HMAC-SHA256 and you regenerate the exact result you were shown.
Every term above is defined in the glossary, and this tool performs step four.
Why this is worth doing at least once
Almost nobody verifies anything, which is what makes the guarantee weak in practice. Checking a single result once tells you whether the operator’s published values actually reconcile — and an operator whose numbers do not reconcile is telling you something important.
Questions
What does a matching result actually prove?
That the operator did not change the outcome after you placed your bet. It committed to a server seed in advance by publishing its hash; if the revealed seed hashes to that commitment and reproduces the result you saw, the result was fixed before you acted. That is a real guarantee, and a meaningful one.
What does it not prove?
That the game is worth playing. Provable fairness says nothing about the house edge, which applies exactly as advertised, and nothing about whether the operator will pay a withdrawal. A perfectly verifiable game can still take your money at a steady, predictable rate — and an operator with flawless fairness proofs can still be slow to pay.
Is my seed sent anywhere?
No. The verification runs in your browser using the Web Crypto API built into the platform. Nothing is uploaded, logged, or stored — you can confirm this by disconnecting from the network and using the tool anyway, which will work perfectly.
My result doesn't match. What now?
Check the mechanical causes first, because they account for nearly every mismatch: a trailing space in a pasted seed, the wrong nonce, or a cursor value the operator handles differently. Different operators also derive game outcomes from the hash in different ways. If everything is correct and it still fails to match, raise it with the operator and keep your records — that is precisely the situation this system exists to surface.
Fair is not the same as favourable.18+ only. Verifying a result confirms it was not tampered with. It does not reduce the house edge, improve your odds, or make gambling profitable.