Provably Fair Verifier: Recompute Any Crash Round in 4 Schemes
Want to verify a crash round yourself instead of trusting the casino? This verifier reproduces the exact crash multiplier from any round on Aviator, JetX, Lucky Jet, Spaceman and 18 more titles. Paste the server seed, paste the client seeds, get the recomputed crash point. Works across SHA-512 (Spribe), SHA-256 (most others), and the four-seed schemes used by Lucky Jet and Aviatrix.
This is a client-side cryptographic recompute of crash-game outcomes. Modern crash games (Aviator, JetX, Lucky Jet, Aviatrix, BGaming titles) publish a hash of the server seed before bets close, then reveal the actual seed plus the client seeds and nonce after the round ends. The crash point is deterministically derived from those inputs through SHA-256 or SHA-512 hashing. Paste them here, and the math runs in your browser via the Web Crypto API. If the crash point we compute matches what the game showed, the round was honest. If not, you have evidence the casino tampered with the result.
How verification works (5 steps)
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1
Server seed commit
Before the round starts, the casino publishes a hash of the server seed. The seed itself stays hidden, but the hash locks it in. The casino cannot rewrite the seed after seeing your bet without breaking the hash.
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2
Client seeds contributed
Depending on the scheme, one to four client seeds enter the calculation. Aviator and Aviatrix use three seeds from the first three players in the round. Lucky Jet adds a fourth from your own client. JetX and BGaming use one client seed.
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3
Hash everything together
Server seed plus all client seeds plus a nonce (round number) get joined into a single string and hashed via SHA-256 or SHA-512. The output is a deterministic 64 or 128 hex-character digest that depends entirely on the inputs.
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4
Extract the fraction
The first 13 hex characters of the digest convert to an integer between 0 and 16^13. Divide by 16^13 to get a fraction h between 0 and 1. This h is the entropy used for the round.
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5
Apply the formula
Plug h into the crash-point formula: (100 - house_edge) / (1 - h) / 100. With Spribe's 3% house edge: a fraction of h=0.5 produces crash at 1.94x, h=0.97 produces 32.33x, h=0.99 produces 97x. About 3% of rounds resolve at exactly 1.00x because the formula returns values below 1.00 in that range - this is the house edge expressed as a distribution, not a bug.
What you can verify here (22 games)
Most crash games on the market use SHA-256 or SHA-512 commit-reveal. We support 23 of the 30 titles reviewed . Pragmatic Play (Spaceman, Big Bass Crash, High Flyer), Evolution (Cash or Crash Live, Red Baron) and Betsoft (Triple Cash or Crash) use lab-audited RNG instead - GLI and iTech Labs certify those titles directly, no client-side seed verification is possible.
Not supported here (lab-audited only)
- Spaceman Pragmatic Play uses GLI/iTech-certified RNG, not client-verifiable provably fair.
- Big Bass Crash Pragmatic Play certified RNG.
- High Flyer Pragmatic Play certified RNG.
- Cash or Crash Evolution Live - physical card draws in studio, not seed-based.
- Red Baron Evolution Live.
- Triple Cash or Crash Betsoft RNG, audited by BMM and iTech Labs.
- Astronaut Provider audit chain only.
- Penalty Shoot Out Hybrid mechanic, lab-audited only.
5 ways to find your seeds
- In Aviator, click the green-shield 'Provably Fair' badge above the round history strip. The latest round shows: server seed (revealed), three client seeds, server seed hash (the commit), and round nonce. Copy all four into the tool with scheme 1 selected.
- In JetX, the History tab shows past rounds with a small Verify button next to each. Click to reveal server seed plus client seed.
- Lucky Jet on 1win exposes its four seeds via the Settings cog inside the game window, then 'Provably Fair'. Copy server seed, your client seed, plus the three other client seeds shown.
- BGaming titles surface seeds via the in-game Info panel. Same pattern: server seed (revealed), client seed, nonce.
- If the casino does not expose any of these, the game is not running provably fair - it is using a certified RNG (Pragmatic Play model) or a hybrid scheme. Check the game review on this site for which model your title uses.
8 frequently asked questions
Is the verification data sent anywhere?
No. The hashing runs entirely in your browser via the Web Crypto API. Your server seed, client seeds, and nonce never leave your device. You can confirm by opening browser DevTools, going to the Network tab, and submitting the form - there are no outbound requests during verification.
What does it mean if the computed crash point does not match what the game showed?
It means one of three things. Most likely you have the wrong nonce or copy-paste error in a seed - check carefully. Less likely the scheme is wrong - try the other variants. Very unlikely but possible: the casino tampered with the result. If you have verified the seed values are correct and the scheme matches the provider's published documentation, but the result still differs, that is grounds to dispute the round with the casino and the regulator. Save screenshots.
Can I predict the next crash point?
No. The server seed for the next round is committed (its hash is published) but the actual seed is hidden until after the round resolves. Without the server seed, the formula cannot be evaluated forward. Anyone selling 'Aviator predictors' or hash-cracking software is selling guesses at numbers that do not exist yet. The math here verifies past rounds, not future ones.
Why does Aviator use SHA-512 while most others use SHA-256?
Both are cryptographically sufficient for this use case - SHA-256 is unbroken and has 256 bits of preimage resistance, more than enough. Spribe's choice of SHA-512 is over-engineering: it doubles the digest length for marginal extra resistance, mostly as a trust signal. Functionally for crash-point math both algorithms produce the same kind of uniform distribution.
Why are some games not supported here?
Pragmatic Play, Evolution Gaming, and Betsoft use a different fairness model - certified RNG audited by labs like GLI and iTech, sometimes Gibraltar Regulatory Authority. The math runs on the provider's server but is not exposed to clients seed-by-seed. Trust comes from regulator enforcement and lab certification, not browser-side recomputation. For those titles, this verifier cannot recompute - check the audit reports linked from each provider review instead.
What is the difference between verifying a round and verifying a session?
This tool verifies one round at a time. To check that a session was fair across many rounds, you would also need the published RTP - say 97% for Aviator - and run thousands of rounds through the same calculation, then compare your sample's average return to 97%. On 10,000+ rounds the average should converge to within statistical margin of the published RTP. If it does not, that is session-level fraud evidence. Per-round verification is the building block; session statistics are the aggregate check.
What if my house edge is different from the default?
Use the Custom scheme. Most providers use 3% house edge (Aviator, Lucky Jet, BGaming, Upgaming). Some use 4% (a few SmartSoft and Turbo Games titles). Some have variable edges by cashout band (JetX sliding RTP). Check the game review for the right number, or read the provider's published documentation.
Can I verify older rounds I screenshot from a session last week?
Yes - as long as the casino still exposes the server seed for that round in its history. Most providers retain provably-fair history for 30 to 90 days. Check the in-game History or Provably Fair tab - if your old round is there with revealed seeds, paste them here. If the seeds are gone (purged), the round is no longer cryptographically verifiable.
