WheelJarHow do I prove a giveaway draw was not rigged?
Every giveaway ends with someone in the comments saying it was fixed. This is the only answer that is not just your word.
Sealed draw for a giveaway
One-offTell us the draw date. We seal a random seed now and publish its fingerprint straight away, then send you the seed itself on the day — so nobody can claim you picked the winner.
Free to use — Pro is for keeping it
This tool, like every other one here, is free and needs no account. A free account keeps three setups and three email alerts. Pro takes the ads off every site we run and lifts that to 200 setups and 50 alerts, adds a public page for any result and lets you embed the tool without our badge.
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How this works
What a commitment scheme proves
And, just as importantly, what it does not.
| Claim | Proved? | Why |
|---|---|---|
| The entry list was not changed after the draw | Yes | The list is part of the hashed commitment |
| The seed was not chosen to pick a favourite | Yes | The seed is fixed by the commitment before the draw |
| The draw was not repeated until it suited | Only if you publish | Each redraw produces a new commitment |
| Every entrant was a real person | No | That is moderation, not cryptography |
| The organiser did not add themselves | Only if the list is public | Publish the list with the commitment |
Publish the commitment somewhere timestamped and public before drawing. Without that step the proof is worth nothing.
Frequently asked questions
What exactly does this prove?
That the entry list and the random seed existed, unchanged, before the draw was made — because the fingerprint you published depends on both, and a fingerprint cannot be reversed or made to match a different input.
Could I still cheat by redrawing until I like the winner?
Only by publishing a new commitment each time, which is visible. The proof is only as strong as publishing the fingerprint somewhere timestamped and public before you draw.
How do people verify it?
They take the seed you revealed, the entry list exactly as you published it, join them with a vertical bar, and hash with SHA-256. Any online SHA-256 tool will do it. If it matches your published fingerprint, the draw stands.
Does randomness come from the browser?
The seed comes from the browser’s cryptographic random source, not from Math.random. Selection is then derived deterministically from that seed, which is exactly what makes it reproducible and therefore checkable.