Provably Fair Verifier
This provably fair verifier takes the revealed server seed, your client seed and the nonce from any Stake Originals bet, then recomputes the exact result the casino should have shown you. Everything runs in your browser. Nothing you paste ever reaches a ChipReign server.
Match means the bet was fair. No match means you’ve got something worth a screenshot and a support ticket. Drop your seeds in below and check a hand right now.
Provably Fair Verifier
Independently verify Stake Originals outcomes. HMAC-SHA256 runs in your browser.
The server seed is only revealed after you change or rotate your seed pair on Stake. The unrevealed one is a hashed commitment.
How Stake's provably fair system actually works
Stake generates every outcome using HMAC-SHA256 with the following inputs:
- Server seed: generated by Stake; you see a hashed commitment before play; the unhashed value is revealed after you rotate seeds.
- Client seed: chosen by you (can be your username or any string).
- Nonce: an integer that increments with every bet on the same server/client seed pair.
The HMAC output (32 bytes) is then converted to a game outcome using game-specific rules:
- Dice, Limbo, Crash: the first 4 bytes become a float between 0 and 1, then a game-specific formula derives the result.
- Plinko: each row uses 4 bytes to decide direction; position at the bottom determines the multiplier.
- Mines: all 25 tiles are shuffled using a Fisher-Yates algorithm seeded by the HMAC bytes.
The system is fair because you can verify every outcome: the server couldn't have chosen a different number at the time, because the hashed commitment was published before your bet.
What provably fair actually means
Provably fair is a cryptographic setup that lets you confirm a casino didn’t move the goalposts after you placed a bet. Before you wager, the casino commits to a secret server seed by showing you its hashed fingerprint. You bring your own client seed. The outcome of every bet comes from combining those two values with a nonce, the bet counter, through HMAC-SHA256.
Here’s the part that matters. The casino has to lock in that server seed in advance, so it cannot change the result once it knows what you picked. When you later rotate your seed pair, the casino reveals the original server seed. You hash it yourself and check it against the fingerprint it gave you up front. If they match, the casino was honest the whole time. The maths does the trust, not the marketing.
How to verify a Stake Originals bet
Verifying a bet takes about a minute once your seed is revealed. You need three things off the casino: the revealed server seed, the client seed that was active for that bet, and the nonce. All three live in the game’s fairness or bet-detail panel.
- On the casino, rotate or change your seed pair. This is what unlocks the old server seed for inspection. You cannot verify a bet on a seed you’re still using.
- Open the bet you want to check and copy its nonce. Each bet on a seed pair has its own number, starting at zero.
- Copy the revealed server seed and the client seed from the same fairness panel.
- Pick the game above, paste all three values, and hit verify. The tool recomputes the raw result and the game outcome.
- Compare it to what the casino showed. Same number, fair bet. Different number, escalate it.
One thing trips people up more than anything else. You’re verifying a bet from a seed pair you’ve already retired, not your live one. That’s by design. A casino that let you see the current server seed could be played against, so the reveal only happens after you move on.
What each game checks
Different Originals turn the same HMAC bytes into different outcomes, so the verifier handles each one on its own terms. The cryptography underneath is identical. The conversion from raw bytes to a result is where they split.
| Game | What the tool recomputes |
|---|---|
| Dice | The roll from 0.00 to 99.99 that decides win or loss against your target. |
| Limbo | The crash multiplier, the point where the rocket cashes out. |
| Crash | The round multiplier from the same byte-to-float method Limbo uses. |
| Plinko | The path the ball takes, left or right at each row, down to its final slot. |
Picked “raw bytes” instead? That mode shows you the underlying HMAC-SHA256 output before any game logic. Useful if you want to audit the cryptography itself rather than trust our conversion. And if you run a Stake Original we haven’t mapped yet, the raw view still proves the server seed reveals correctly.
When the seeds don’t match
A mismatch is rare, and nine times out of ten it’s a copy-paste slip rather than a rigged casino. Before you accuse anyone of fraud, rule out the boring stuff first.
- Wrong nonce. The bet number has to match the exact hand, and it’s easy to grab the one above or below it.
- Wrong seed pair. The client seed must be the one that was live for that bet, not your current one.
- A trailing space or a missing character pasted into the seed field. Seeds are long. Copy the whole string.
- Plinko rows set wrong. The path depends on the row count, so 16 rows verified against an 8-row bet won’t line up.
Clean all that up and still get a mismatch? Now it’s interesting. Screenshot the bet, the fairness panel and the verifier output, then open a support ticket and ask the casino to explain the discrepancy. A legitimate provably fair operator will walk you through it. If support gets cagey or the numbers never reconcile, that tells you everything about whether to keep your bankroll there. Our guide to spotting a crypto casino scam covers what to do next.
Which casinos support provably fair
Provably fair is standard on the crypto-native operators and absent almost everywhere else. The big Originals studios run it on dice, limbo, crash, plinko and a handful of others. Regular slots from third-party studios are not provably fair, they’re certified by labs instead, so this tool only covers the in-house Originals.
- Stake.com wrote the Originals playbook the rest of the industry copied.
- BC.Game and Roobet run their own provably fair in-house games on the same HMAC-SHA256 model.
- Shuffle and most of the other crypto rooms in our crypto casino reviews support it too.
State-licensed real-money casinos don’t use provably fair at all, and they don’t need to. Their RNGs are audited by independent test houses and policed by regulators like the New Jersey DGE. Different trust model, same goal. If you’re weighing one against the other, our crypto versus real-money breakdown lays out the trade-offs.
Provably fair verifier FAQ
Is the provably fair verifier free to use?
Yes, completely free, with no signup and no limit on how many bets you check. The HMAC-SHA256 maths runs in your browser, so we never see your seeds.
Do I have to reveal my server seed first?
You do. A casino only releases the server seed after you rotate your seed pair, and that reveal is what makes verification possible. You cannot check a bet on a seed you’re still actively playing.
Does a passing check mean the casino is safe overall?
It means that specific bet was fair, which is a big deal, but it’s not the whole picture. Provably fair says nothing about whether the casino pays withdrawals, holds a real licence or treats you straight at KYC. Check the operator’s licence and read the full review before you trust a room with real money.
Why doesn’t my result match what the casino showed?
Almost always it’s the nonce, the wrong seed pair, or a stray character in a pasted seed. Double-check those three. A genuine mismatch after a clean entry is worth a support ticket and a screenshot.
Play responsibly. Verifying fairness doesn’t change the house edge, and no maths makes gambling a way to earn. 18+, or 21+ where required. Help is free and confidential: US 1-800-MY-RESET, UK GamCare 0808 8020 133, AU 1800 858 858. More in our responsible gambling hub.