What this tool does: Paste seeds from a completed crash game round to independently recalculate the crash point. Supports Stake-style (232 formula) and Bustabit-style (52-bit formula) implementations. All calculations run in your browser — no data is sent to any server.
This is an independent verification tool. Never trust a casino’s built-in verifier alone — always cross-check with an independent tool like this one. If the calculated crash point matches what you saw in the game, the round was not tampered with.
Enter Seeds
Test Vectors
Use these examples to confirm the verifier is working correctly on your device:
| Mode | Server Seed / Game Hash | Client Seed / Block Hash | Nonce | House Edge | Expected Result |
|---|---|---|---|---|---|
| Stake | serverseed123 | clientseed456 | 0 | 1% | Enter these values in Stake mode to see a result. Then re-enter the same values — the result must be identical every time. |
| Bustabit | 77b271fe12e97... (64 hex chars) | 0000000000000000... (block hash) | — | — | Enter these values in Bustabit mode. The result should be a specific multiplier or “1.00x (instant crash)” if divisible by 101. |
Determinism test: Enter any seeds, note the result, reload the page, enter the same seeds — the result must be identical. If it changes, something is wrong with your browser’s crypto implementation (extremely rare).
Supported Platforms
| Platform | Mode to Use | Method | Where to Find Seeds |
|---|---|---|---|
| Stake | Stake | HMAC-SHA256, 232 formula | Settings → Fairness → Seeds tab |
| Roobet | Stake | HMAC-SHA256, 232 formula | Game → Fairness panel |
| Bustabit | Bustabit | HMAC-SHA256, 52-bit formula | Game history → Verify link |
| Any platform | Manual SHA-256 | Plain SHA-256 hash | Varies — check platform docs |
How This Verifier Works
Stake Mode (232 formula)
The verifier combines your server seed, client seed, and nonce using HMAC-SHA256: hash = HMAC-SHA256(serverSeed, clientSeed:nonce:0). It takes the first 8 hex characters, converts them to a 32-bit integer, and applies: crashPoint = max(1, (2^32 / (int + 1)) × (1 − houseEdge)). This matches the Stake Originals implementation.
Bustabit Mode (52-bit formula)
The verifier combines the game hash with the Bitcoin block hash: hash = HMAC-SHA256(gameHash, blockHash). It takes the first 13 hex characters (52 bits), checks for instant crash (first 8 hex chars divisible by 101), and applies: crashPoint = floor((100 × 2^52 − int) / (2^52 − int)) / 100. The ~1% instant crash rate enforces the house edge.
Manual SHA-256
For platforms with non-standard implementations. Enter any string in the Input field — the verifier computes its SHA-256 hash. If you also paste the hash that the platform published before the round into the Expected SHA-256 field, the tool compares them automatically: green for match (data wasn’t altered), red for mismatch (double-check your input before concluding manipulation).
→ For the full mathematical breakdown, see our Crash Game Algorithm Guide.
→ For step-by-step verification per platform, see our Provably Fair Verification Guide.
→ To understand what RTP and house edge cost you, see our RTP & House Edge Guide.
Frequently Asked Questions
Is this verifier independent from the casinos?
Yes. This tool runs entirely in your browser using the Web Crypto API (crypto.subtle). No data is sent to any server — not ours, not the casino’s. You can verify this by opening your browser’s DevTools (F12 → Network tab) and confirming zero outbound requests when you click “Verify Round.”
Why doesn’t my result match the game?
The most common reasons: (1) you selected the wrong mode — Stake and Bustabit use different formulas; (2) the nonce is incorrect — it resets to 0 when you rotate your server seed on Stake; (3) you’re using the hashed server seed instead of the revealed (unhashed) one; (4) the platform uses a non-standard implementation that this tool doesn’t cover. A mismatch usually means incorrect inputs, not manipulation.
Can I verify BC.Game rounds with this tool?
Possibly, but with caution. BC.Game’s Crash implementation may differ from the Stake-style 232 formula used in this tool. Before relying on results, test with a round where you already know the correct crash point from BC.Game’s own verifier. If the results match, the tool works for your BC.Game version. If not, BC.Game may use a different formula variant.
Can I verify Aviator rounds with this tool?
No. Aviator uses SHA-512 (not SHA-256) and derives the client seed from the first three players who bet in each round. This tool does not implement that algorithm. For Aviator, use Spribe’s official verifier alongside an independent SHA-512 calculator.
Is my data safe?
Yes. All calculations happen locally in your browser using crypto.subtle. You can disconnect from the internet after loading this page and the verifier will still work.
What does “instant crash” mean in the result?
In the Bustabit formula, approximately 1 in 101 rounds crashes at exactly 1.00x regardless of the hash value. This is how the ~1% house edge is enforced. If the verifier shows “1.00x (instant crash),” it means the hash triggered this mechanism — it’s not a sign of manipulation.