Provably Fair Verifier
Confirm any crypto-casino bet was decided before you played and never tampered with. Paste your seeds and nonce below, and everything is calculated in your browser, so your seeds stay private.
🔒 100% private: all maths runs in your browser with the Web Crypto API. Your seeds are never sent to RTPspy or anyone else.
How to verify a bet in 3 steps
- In the casino, rotate your server seed. This reveals the raw server seed used for all your previous bets.
- Open the bet you want to check and note its nonce, plus your client seed.
- Paste all of it above with the hash you were shown before playing. A match on both the commitment and the result means that round was provably fair.
What is a provably fair verifier?
It is a tool that re-runs the cryptography behind a casino bet. Using the revealed server seed, your client seed and the nonce, it reproduces the exact result the casino showed you. If the numbers match, that round was locked in before you bet and could not have been changed.
Is it safe to paste my seeds here?
Yes. This verifier runs 100% in your browser using the Web Crypto API. Your server seed, client seed and nonce are never sent to RTPspy or any server. You can disconnect from the internet and it still works.
Why doesn't my result match?
Almost always a small input error: using the hashed server seed instead of the revealed one, the wrong nonce, or a casino that converts the HMAC differently. Also note the Dice figure here uses the Stake-engine method, and other casinos may map the same HMAC another way.
Does a match prove the game is fair long-term?
No. Verification proves one round used the committed seed data. It does not prove the game's RTP, that the house edge is low, or that future bets are predictable. Anyone selling a tool that predicts future results is running a scam.
18+. Verification confirms a round used its committed seeds; it does not guarantee profit or predict future bets. RTPspy is independent and not affiliated with any casino named.