Provably fair means you can recompute a game result yourself and confirm the casino did not change it after you bet. The mechanism is straightforward once you have seen it, but implementations differ enough between casinos that a generic verifier will not reproduce their numbers.
Verification details are recorded per casino, because the conversion step is where implementations diverge.
| Casino | Welcome bonus | Wagering | Min deposit | Claimed payout | Our score |
|---|---|---|---|---|---|
| BC.Game | Four deposit bonuses up to 360% | 40x | $5 | 1 hour | 9.9 |
| Wild.io | 350% across three tiers and 200 free spins | 40 to 50x | $20 | 0 to 24 hours | 9.6 |
| LuckyRollers | 100% up to 30,000 USDT + 100 free spins | 40x | $20 | 0 to 4 hours | 9.5 |
| Instant Casino | 200% up to $7,500 + 10% cashback | 15x | EUR 20 | Near instant | 9.5 |
| Lucky Block | 200% up to $25,000 + 50 free spins | 60x | $20 | 0 to 24 hours | 9.5 |
| Wall Street Memes | 200% up to $25,000 + 50 free spins | 60x | $20 | 1 to 3 hours | 9.4 |
| Mega Dice | 200% up to 1 BTC + 50 free spins | 60x | $20 | 0 to 24 hours | 9.4 |
| Cryptorino | 100% up to 1 BTC | 66x | None | 15 minutes | 9.0 |
| BetPanda | 100% up to 1 BTC | 80x | 0.1 uBTC | Instant | 8.9 |
| Thrill Casino | none advertised | none | none stated | 1 to 30 minutes | 8.9 |
These are the 10 highest scoring crypto casinos in the register, with the provably fair originals each one lists. Listing an original is not proof that it is fair, so check any round with the verifiers on our game pages.
Our score: 9.9
Our score: 9.6
Our score: 9.5
Our score: 9.5
Our score: 9.5
Our score: 9.4
Our score: 9.4
Our score: 9.0
Our score: 8.9
Our score: 8.9
Provably fair is a commitment scheme that lets you check a result after the fact. The casino commits to a secret before you bet, you contribute a value it cannot predict, and the outcome is derived from both.
The point is not that the game is generous. A provably fair game still carries a house edge, and the edge is usually published. What the scheme proves is that the casino did not alter the outcome once your bet was placed.
A provably fair game lets you check each result yourself, while an RNG game asks you to trust a lab that audited the software. The two answer different questions, and most crypto casinos run both side by side.
RNG games run on a random number generator that a testing lab such as eCOGRA, iTech Labs or GLI has examined. The certificate covers the software version that was tested, and you cannot recheck any single spin.
| Question | Provably fair | Lab-certified RNG |
|---|---|---|
| Who checks the result | You, with the revealed seeds | A testing lab, on the game code |
| When it is checked | After each bet, once you rotate seeds | At certification and on later audits |
| What it covers | One result at a time | The statistical behaviour of the software |
| Typical games | Casino-built originals such as dice and crash | Third-party slots and virtual table games |
| Main weakness | Says nothing about the edge or payouts | You cannot verify an individual result |
Neither scheme proves a casino will pay you. Check which one covers the game you are playing before you treat either as a guarantee.
Three inputs produce every result, and each exists to close a specific gap. Remove any one of them and the scheme stops proving anything.
A random string the casino generates and keeps secret. Before you play it publishes the SHA-256 hash of that string, which commits it to a value without revealing it. Because SHA-256 cannot be reversed, that hash is a promise it cannot later break.
A string contributed by you, usually generated by your browser and editable in the game settings. It exists so the casino cannot precompute outcomes, because it does not control both inputs.
A counter that increments with every bet on the same seed pair. It lets one server seed produce a long sequence of distinct results, and it means each bet in that sequence is independently checkable.
The outcome is derived by running HMAC-SHA256 over the client seed and nonce, keyed with the server seed. The resulting bytes are converted to a number, and that number maps onto the game.
Verification happens after you rotate your seed pair, because the casino can only reveal the server seed once it can no longer be used. The sequence is the same everywhere even though the final step differs.
Copy it before you start playing. This is the commitment, and without it recorded beforehand you have nothing to compare against later.
Both are shown in the game interface. The nonce for a given bet is fixed once that bet is placed.
Changing your seed retires the current server seed, and the casino then publishes it in plain text. Results from the old pair remain verifiable.
Hash the revealed server seed with SHA-256 and compare it to the hash you recorded in step one. If they differ, the casino swapped the seed and nothing else is worth checking.
Run HMAC-SHA256 with the revealed server seed as the key and your client seed and nonce as the message, then apply the casino’s documented conversion to turn the output into a game result.
The commitment step is identical everywhere, but the conversion from hash output to game result is not. Casinos differ in three places, and a mismatch in any one produces a wrong answer that looks like cheating when it is not.
Use the casino’s own published verifier or its documented formula. A verification that fails because you used someone else’s conversion tells you nothing about the casino, and it is the most common reason people conclude a game is rigged when the maths is fine.
Each game converts the same hash output differently, and the house edge is built into the payout rather than the randomness. Edges below are typical for crypto originals and vary by casino and configuration, so check the published figure rather than assuming.
The float maps directly onto a number in a fixed range, and you bet on whether the roll lands above or below a target you set. Payout scales inversely with your win chance, with the edge taken off the top.
The simplest mapping, usually the parity of a value derived from the digest. A fair coin would pay 2x, so the published payout tells you the edge directly.
The hash produces a multiplier at which the round ends, drawn from a distribution weighted heavily toward low values. A small proportion of rounds are forced to an instant bust, and that proportion is the house edge.
Mathematically the same as crash without the timing element. You choose a target multiplier and the hash determines whether the round reached it.
The digest seeds a shuffle that places mines on a grid. Each safe tile raises the multiplier by an amount derived from the remaining probability, which is why the curve steepens as you continue.
Each row is a binary decision taken from successive bits of the digest, producing a binomial distribution across the buckets. Centre buckets are common and pay least, edges are rare and pay most.
Casino-built originals such as dice, crash, mines, limbo, plinko and coin flip are the games usually covered, and third-party slots are not. The scheme only works where the casino generates the result itself.
A game that offers no seed panel and no Verify option runs on an RNG, whatever the lobby label says. The game’s info screen or the casino’s fairness page should list exactly which titles support verification.
No, not without breaking the hash it published beforehand. The commitment is made before you play, and SHA-256 is one-way, so no different server seed will produce the same hash.
What a casino can do is generate many server seeds in advance and choose which one to commit to, which is why the client seed matters. Because you control an input it cannot predict, pre-selecting a favourable seed gains it nothing.
A committed result cannot be changed after your bet without breaking the published hash, but the scheme leaves other gaps open. Those gaps are about how the casino runs the system and not about the maths.
A game can be expensive to play without being rigged in the sense that matters here. What the scheme rules out is a casino rewriting a result after it has seen your bet.
It proves one narrow thing, which is that a specific result was not altered after your bet. Several risks sit entirely outside the scheme, and conflating them is the most common mistake players make here.
Provably fair covers game results only, so it cannot tell you whether a casino is safe, licensed or willing to pay. Safety comes from the licence, the owner, the terms and the settlement record.
Check which regulator issued the licence and what that regulator can compel an operator to do. Then read the withdrawal terms and the payout record, because a fair game does not help if the balance is held. Our scoring weights settlement above game fairness for that reason.
A casino only claims to be provably fair when it cannot show you the commitment, the formula or a way to rotate your seeds. A badge on the homepage proves nothing without those three.
The most common myth is that provably fair means better odds, and it does not. The scheme proves a result was not altered and says nothing about how generous the game is.
We rate a provably fair casino on what its own terms and records show, and we give settlement more weight than game fairness. Each figure is quoted from the casino’s terms with the day we read it.
The full weighting is on the methodology page.
Choose a provably fair casino by checking that it publishes its formula, lets you rotate seeds and pays withdrawals on time. Fairness features count for little if the settlement record is weak.
The multiplier is not the cost. Turnover is, and it is the multiplier applied to a base that varies by casino. The column below works out what clearing a $100 bonus actually requires at each provably fair casino in the register.
| Casino | Welcome bonus | Wagering | Turnover on $100 | Min deposit | Our score |
|---|---|---|---|---|---|
| Instant Casino | 200% up to $7,500 + 10% cashback | 15x | $1,500 | EUR 20 | 9.5 |
| BC.Game | Four deposit bonuses up to 360% | 40x | $4,000 | $5 | 9.9 |
| Wild.io | 350% across three tiers and 200 free spins | 40 to 50x | $4,000 | $20 | 9.6 |
| LuckyRollers | 100% up to 30,000 USDT + 100 free spins | 40x | $4,000 | $20 | 9.5 |
| Lucky Block | 200% up to $25,000 + 50 free spins | 60x | $6,000 | $20 | 9.5 |
| Wall Street Memes | 200% up to $25,000 + 50 free spins | 60x | $6,000 | $20 | 9.4 |
| Mega Dice | 200% up to 1 BTC + 50 free spins | 60x | $6,000 | $20 | 9.4 |
| Cryptorino | 100% up to 1 BTC | 66x | $6,600 | None | 9.0 |
| BetPanda | 100% up to 1 BTC | 80x | $8,000 | 0.1 uBTC | 8.9 |
| Thrill Casino | none advertised | none | nothing to clear | none stated | 8.9 |
Two things inflate that figure further and neither is in the headline. Where terms say the requirement applies to deposit and bonus rather than bonus alone, the base doubles. And where slots count 100% toward clearing but table games count 10%, the same requirement takes ten times the turnover on blackjack.
The seed scheme on this page is centralised, because the casino’s own server generates the secret and the result. An on-chain design moves the random number onto a blockchain, where a verifiable random function produces it with a proof anyone can check.
The difference is who you have to trust. With server seeds you trust the casino to keep the unrevealed seed secret and to run the conversion correctly, and with on-chain randomness you trust the contract code and the oracle that supplies the number.
Provably fair does not make a game safer to play, because the house edge still applies to every bet. Set a deposit limit before you start and treat the fairness proof as a check on the game and not as a reason to stake more.
Fast rounds in crash, dice and plinko make it easy to place hundreds of bets in a session. If gambling stops being fun, free and confidential support is available from GambleAware.
Provably fair is a system that lets you recompute a game result and confirm it was not changed after you bet. The casino commits to a hashed secret beforehand and reveals it afterwards so you can check.
Rotate your seed pair so the casino reveals the server seed, hash it and compare against the commitment it published earlier. Then recompute the outcome using the casino’s documented formula.
The individual result cannot be altered after your bet without breaking the published hash. The house edge is set separately in the payout, so a game can be both verifiable and expensive to play.
Almost always because the conversion step differs from the one you used. Casinos construct the HMAC message and consume digest bytes differently, so use their own verifier rather than a generic tool.
Most slots are not provably fair at all. They come from third-party studios running their own RNG, and only a casino’s in-house originals are usually covered by the scheme.
The nonce is a counter that increases with each bet on the same seed pair. It lets one server seed generate a long run of distinct, independently checkable results.
A provably fair checker recomputes a round from three inputs, the server seed, your client seed and the nonce, and shows whether the result matches what the casino displayed.
Our free verifiers do this in your browser for dice, limbo, plinko, mines, crash and coin flip, and they print every step so you can compare the digest and the result with the casino's. Nothing you enter leaves your device.
No. A predictor cannot know the outcome of a provably fair round, because the server seed that decides it stays secret until you rotate your seeds.
A tool that claims to predict the next result is guessing or selling something. The only thing you can check is a round that has already happened, which is what a checker does.
Provably fair is a real guarantee within narrow limits. It proves a specific result was not tampered with, and it proves nothing about the edge you are playing against or whether a balance will actually be paid out.
Treat it as one input rather than a verdict. A casino running verifiable games that settles withdrawals slowly is still a slow casino, which is why settlement carries more weight in our scoring than game fairness does.
18+18+ only. Gambling carries real risk of loss and the casinos covered here are offshore, which means limited recourse if something goes wrong. Free, confidential support is available at GambleAware and the SAMHSA national helpline.
