How To Verify Provably Fair Results (Step by Step)

Published 29 May 2026 · 7 min read

Provably fair is only useful if you actually verify rounds. This guide walks through the exact procedure — no programming required — so you can re-compute a Goemon round (or any properly-implemented crash game) and confirm it wasn't manipulated.

What you need before starting

A finished round you want to check.
Access to the game's round history or "Provably Fair" panel.
Any SHA-256 and SHA-512 calculator (online tools work; this one is a common pick).
The game's published verification formula. Goemon ships with one; check the in-game info panel.

Step 1: Open the round history

In Goemon, the previous-rounds strip is at the top of the screen. Click it (or open the "Provably Fair" tab) to expand into the full history. Pick the round you want to verify. You'll see:

The server seed hash (the SHA-256 commitment that was published before the round started).
The revealed server seed (a long alphanumeric string, only shown after the round closed).
The three client seeds contributed by the first three wagering players.
The actual crash point (the multiplier the round resolved at).

Step 2: Confirm the server seed matches its hash

Copy the revealed server seed. Paste it into a SHA-256 calculator. Compare the result to the pre-round server seed hash.

If they match → the operator did not change the seed mid-round. The commitment held. ✅

If they don't match → the operator changed the seed, which is the worst kind of cheating. Walk away and post your finding publicly. ❌

Step 3: Combine the seeds and hash

Now you reconstruct the round's randomness. In Goemon's published scheme, the formula is:

hash = SHA512(serverSeed + clientSeed1 + clientSeed2 + clientSeed3)

Concatenate the four strings (in the order documented in the game's info panel — exact order matters), paste into a SHA-512 calculator, and copy the resulting 128-character hex hash.

Step 4: Map the hash to a multiplier

The game's mapping formula converts the hash into a number, and that number into a crash multiplier. Different games use different formulas, but the most common pattern is:

Take the first 13 characters of the hash (in hex). Convert to a decimal integer.
Divide by 2⁵² (the maximum possible value of those 13 hex chars).
Apply the game's specific transformation. A common formula is: crashPoint = (100 × 2⁵² − h) / (2⁵² − h) / 100 — but Goemon's exact formula is published in its info panel, so use that.
The result is the multiplier the round should have crashed at.

Step 5: Compare

If your computed multiplier matches the actual crash point of the round → ✅ The round was honest. The math reproduces.

If they don't match → ❌ Something is wrong. Re-check your inputs (most failures are from copy-paste whitespace or wrong concatenation order). If you've re-checked carefully and the numbers still don't match, document it and contact support immediately. That's a verifiable claim of manipulation.

Faster: use an online verifier

Most reputable crash games provide a built-in verification tool, and several third-party sites maintain open-source verifiers for popular titles. Search for "[game name] provably fair verifier". These tools automate steps 2–5; you paste seeds, they spit out the multiplier. If a game has no verifier and no published formula, that's a sign to play elsewhere.

What honest verification feels like

The first time you verify a round, expect 5–10 minutes of fumbling. After that, it takes 30 seconds. Most players verify a handful of rounds when they first try a game — usually one big win and one big loss — to confirm the math holds. Once you've seen it work, you don't need to verify every round; you just need to know you can.

Frequently Asked Questions

Do I need to be a programmer to verify a round?

No. Any online SHA-256 and SHA-512 calculator can do the math. You're copying strings, hashing them, and comparing the result to a published number.

What if the verification fails?

Re-check that you used the exact seed values (no leading or trailing whitespace) and concatenated them in the order the game's documentation specifies. If verification still fails, that is a serious red flag — contact the operator's support and ask for an explanation. Document the discrepancy.

Can I verify a round during play, or only after?

Only after. The server seed is only revealed once the round closes, which is what makes the commitment meaningful. During play, you can only see the hash, not the seed itself.