Add your entries
Emails or social handles, plus a prize for each place.
Duplicates are removed.
Giveaways people can actually trust.
Seal your entry list, let a Bitcoin block that doesn't exist yet pick the winners, and give every participant a link to check it was fair.
No tokens, no wallet, no crypto knowledge needed — Bitcoin is only the source of randomness. Free for now · Why we built it
How it works, in under a minute.
01
Set it up
Name it, set the prizes, and pick a future Bitcoin block to draw from.
02
Add entries
Upload a CSV or paste emails and handles. Repeats are merged for you.
03
Entries close
Hours before the draw, the list is sealed into one fingerprint and stamped on Bitcoin.
04
The block draws
Once it's mined, its hash shuffles the list. The top spots win, in prize order.
How it works
Seven steps. Every one provable.
Pick the draw block
Choose a time; we suggest the Bitcoin block due then.
Nobody knows that block's hash until it's mined.
Lock the list
Hours before the draw, entries, prizes and block are sealed into one fingerprint.
Change anything and the fingerprint changes.
Timestamp it on Bitcoin
OpenTimestamps anchors the fingerprint within hours — long before the draw block.
Only a hash leaves the server.
Participants check their entry
Type a handle or email; the browser checks the proof.
A proof reveals only your own entry.
The block picks the winners
The mined block's hash shuffles the locked list.
Same list + same block = same winners.
Anyone can verify
The public page re-runs every step in the browser.
Change one entry or winner and a check fails.
Why it's fair
What nobody can do — including us.
No one picks the winners
A Bitcoin block's hash does — and nobody knows it until the block is mined. Not the organizer, not us.
The list can't change after it locks
It's sealed into one fingerprint and timestamped on Bitcoin hours before that block exists.
A result can't be re-rolled
The block is fixed before entries close. Same list, same block, same winners — every time.
No one is quietly left out
Every participant can check their own entry against the fingerprint, without seeing anyone else's.
~10 min
A new block, and a new unpredictable hash
Your locked list, stamped on the chain
Open source
Verify in the browser or from the CLI
Questions
The short answers.
Do participants need Bitcoin or a wallet?
No. Bitcoin is only the source of randomness; checking an entry or a result takes a browser.
Why does the list lock hours before the draw?
So the timestamp confirms first. That's the proof the list existed before the winning block did.
What do participants see?
A public page to check their entry by email or handle, a countdown to the block, and the draw to re-run once it's done.
Does the entry list have to be public?
No. A private list publishes only its fingerprint, and each person can still check that they're in.
How big can a list be?
Millions of entries, from CSV files or pasted lists. Repeats are merged and invalid rows are reported back to you.
Open by default
The protocol is public. So is the verifier.
Run your next giveaway in minutes.
Built for creators and brands · millions of entries · free to verify