Tools for checking a casino yourself

Two calculators that run in your browser. Nothing you type leaves this page.

Bonus calculator

A bonus has to be wagered before you can withdraw it. This estimates what that wagering costs on average, so you can see what the bonus is really worth.

Your deposit Bonus match (%) Maximum bonus Wagering (× times) Wagering applies to Game return to player (%)

An average over many players, in whatever currency you entered. Your own result will vary, and maximum-bet or game-restriction rules can make a bonus worth less. Not financial advice.

Provably fair verifier

After a bet, the casino reveals its server seed. Paste the seeds here to recompute the result and check the seed matches the hash you were shown beforehand.

Server seed (revealed after the bet) Server seed hash (shown before the bet) Client seed Nonce (bet number)

Enter the seeds and select Verify result.

Uses HMAC-SHA256 of "client seed:nonce" keyed with the server seed, and turns the first 8 hex characters into a roll from 0 to 99.99. This is the most common dice formula, but casinos differ, so compare with the formula in the casino's own fairness page.

Common questions

How is the bonus value worked out?

The bonus amount minus the average loss from wagering it: the total you must bet multiplied by the game's house edge.

Does the fairness checker send my seeds anywhere?

No. Both tools run in your browser and nothing you type leaves the page.