Provably fair games let you check every result yourself, with maths instead of trust. Here are the licensed crypto casinos that offer them, a plain-English explanation of how it works, and a verifier you can use on your own bets.
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Ranked on how checkable they are: casinos that publish both their exact method and their house edge come first, because you need both to verify a bet and to know what it costs you.
| Provably fair games | Dice, Crash, Mines, Plinko, Keno |
|---|---|
| Method | HMAC-SHA512 with server and client seeds |
| House edge | 1% on every Original |
Publishes both the method and the house edge for every Original, which is everything you need to check a bet and price it.
| Provably fair games | Dice, Plinko, Limbo, HiLo, Keno |
|---|---|
| Method | SHA-256 provably fair |
| House edge | Varies by game |
Documented SHA-256 system across its five in-house games. Dice is a good place to start checking your own results.
| Provably fair games | 17 Originals, including Dice, Crash, Limbo, Mines and Plinko |
|---|---|
| Method | Server and client seeds |
| House edge | 1% to 3% (97–99% RTP) |
The widest range of provably fair games here. Edges vary from 1% to 3%, so compare RTPs before you pick a game.
| Provably fair games | Dice, Plinko, Mines, Crash, Limbo |
|---|---|
| Method | Server and client seeds |
| House edge | About 1% |
A standard set of Originals at around 1% edge. Fine for checking results, with fewer games than BetBolt.
| Provably fair games | Crash, Plinko and instant-win games |
|---|---|
| Method | Server seed hash published before each bet |
| House edge | Not published |
Shows the server seed hash before you bet, which is the core of provable fairness, but does not publish titles or house edges in full.
In an ordinary online casino, the result of your bet comes from a random number generator on the casino's server. You can't see it, so you trust the casino and whoever certified it. Provably fair replaces that trust with a simple trick from cryptography: the casino locks in its half of the randomness before you bet, in a way it can't change, and shows you proof afterwards.
A long random string the casino generates and keeps secret until you change seeds. Before you bet, it shows you only the seed's hash.
A string you can set to anything. Because the casino commits to its seed first, it can't pick one that beats yours.
A number that goes up by one with every bet, so each bet with the same seed pair gets a different result.
A hash function like SHA-256 turns any input into a fixed-length fingerprint. It only works one way: you can't get the seed back from the hash, and you can't find a different seed with the same hash. So when the casino shows you the hash before you play, it has committed to that exact server seed. If it swapped the seed later, the hash wouldn't match, and you'd see it.
Most casinos combine the three with HMAC, a keyed hash. The server seed is the key, and your client seed and nonce are the message. The output is a long string of random-looking bytes that nobody could predict without both seeds. The game then turns those bytes into a result. For dice, the most common method takes the first four bytes, turns them into a number between 0 and 1, and scales it to a roll from 0.00 to 100.00.
This runs entirely in your browser: nothing you type is sent anywhere. It uses the standard dice method described above (HMAC of client seed:nonce, first four bytes, roll 0.00 to 100.00). Casinos document their own formulas, and some differ, so if your result doesn't match, check the casino's fairness page for its exact method.
It means you can check, after the bet, that the result was fixed before you played and was not changed. The casino commits to a secret server seed by showing you its hash first, you add your own client seed, and the result is calculated from both. When the server seed is revealed, you can recalculate every result yourself.
No. It proves the result was not tampered with. It does nothing to the house edge. A provably fair dice game with a 1% edge still keeps 1% of everything you bet over time.
Almost never. Provably fair only covers a casino’s own in-house games, such as Dice, Crash, Plinko and Mines. Slots from studios like Pragmatic Play or Hacksaw run on certified random number generators instead, which you have to trust rather than check.
Rotate (change) your seed pair in the casino’s fairness settings, which reveals the old server seed. Check its SHA-256 hash matches the hash you were shown before betting. Then put the server seed, your client seed and the bet’s nonce into a verifier, like the one on this page or the casino’s own, and compare the result.
Because the client seed is your half of the randomness. If you set it yourself, the casino could not have picked a server seed that works against it, since it committed to the server seed before knowing yours.
It cannot change a verified result, but it can still do plenty that hurts you: slow or refuse withdrawals, confiscate winnings under vague terms, or run a high edge. That is why we check licences, terms and complaints as well.