Provably Fair Verification

Verify any RBXChance coinflip instantly. Paste the seeds that were revealed after the game and we will reproduce the outcome using the exact algorithm that powers the live platform.

Validate a Coinflip

Enter the server seed, client seed, and wager values. Everything is calculated locally in your browser using SHA-256 hashing.

How Coinflip Validation Works

  1. Hash Generation: We combine server_seed:client_seed:nonce and hash it using SHA-256.
  2. Random Number: We take the first 13 characters of the hash, convert to an integer, and divide by 2^52 to get a float between 0 and 1.
  3. Weighted Odds: The random float is compared against the creator's odds (Creator Value / Total Value).
  4. Winner Determination: If Random Float < Creator Odds, the Creator wins. Otherwise, the Joiner wins.

Need the Game Seeds?

Every completed RBXChance game displays its provably fair metadata:

  • The server seed hash appears in the fairness modal before the coinflip begins.
  • The server reveals the unhashed seed as soon as the game completes.
  • Your browser stores the client seed that was used for the roll.
  • Paste those values here to independently verify the outcome.