Provably fair · proofs on Solana

Pick winners nobody can dispute.

VerifyDraw selects giveaway winners, raffle winners, and airdrop recipients with verifiable randomness — and publishes a proof page anyone can check in their own browser. Not “trust us, it was random.” A cryptographic proof that it was.

Try the draw engine — right here

This demo uses your browser’s randomness. Paid draws use on-chain verifiable randomness with a public proof like this one.

How a draw becomes undisputable

Three mechanical guarantees replace “just trust the person pressing the button.”

1

The list is locked first

Your entrant list is hash-committed before the draw. Nobody can add, remove, or reorder entrants afterwards — the proof would fail loudly.

2

Randomness nobody controls

The outcome comes from a VRF on Solana (the vrand protocol): unpredictable before the draw, provable after it. Not even we can steer it.

3

Anyone can recompute it

Winners derive from the VRF output with a bias-free, deterministic algorithm. The proof page recomputes them in your browser — offline, forever.

Built for draws people argue about

Giveaways & raffles

Paste names, wallets, or ticket numbers — weighted or equal. Announce winners with a proof link instead of a screenshot.

Token-holder airdrops

Point at any Solana token or NFT collection. We snapshot holders and draw winners weighted by balance — snapshot criteria published in the proof.

Whitelists & allocations

Oversubscribed mint? Limited drop? Select fairly and show your community exactly how.

APIs & AI agents

An AI saying “I picked randomly” proves nothing. Agents and apps can call VerifyDraw for randomness that comes with receipts. API coming soon.

Every draw ships its evidence

A VerifyDraw proof page is a single self-contained file: the winner set, the entrant-list commitment, the VRF output and proof, and the verifier itself. Click one button and your browser recomputes the entire draw. If one byte had been tampered with, verification fails.

Open the live demo proof →

winners · 5 of 200 entrants
list hash · sha256:ca917e…
vrf output · 4d1f09…
request · DEhDe3…tjFP (Solana)
✓ Verified — winners recomputed from the VRF output match this page exactly.

Pricing

Pay per draw in SOL. No accounts, no subscriptions to start — self-serve checkout is landing shortly; until then we run your draw within hours.

List draw
0.05 SOL / draw
  • Up to 1,000 entrants
  • Weighted or equal chances
  • Public proof page
Request a draw
Holder draw
0.5 SOL / draw
  • Any Solana token or NFT collection
  • Holder snapshot + criteria in the proof
  • Balance-weighted or equal draw
  • Winner list ready for airdrop
Request a draw
Big lists
0.1–0.25 SOL / draw
  • Up to 25k entrants — 0.1 SOL
  • Beyond that — 0.25 SOL
  • Same proof, any scale
Request a draw

Questions people ask

How do I verify a draw?

Open its proof page and press “Verify this draw in your browser.” Your browser recomputes the winners from the on-chain VRF output and the hash-committed entrant list, using the same open algorithm that produced them. No server involved — it works offline, forever.

Where does the randomness come from?

From a verifiable random function (VRF) on Solana via the vrand protocol. The output is unpredictable before the draw and comes with a cryptographic proof after it — checkable by anyone, controllable by no one.

Is this gambling?

No. VerifyDraw is a selection tool: it picks winners from a list you provide, for giveaways, promotions, and distributions. Nobody purchases chances through VerifyDraw.

Can VerifyDraw rig a draw?

Not without getting caught. The entrant list is committed before the randomness exists, the randomness comes from an on-chain VRF we don’t control, and the derivation is deterministic — any tampering makes the public proof fail verification.

What do weighted draws mean?

Entrants can hold multiple “tickets” — a wallet holding 500 tokens can have 500× the chance of a wallet holding 1. The proof page states the weighting rule and the full ticket table, so odds are public too.