If you've ever run (or entered) a giveaway on Hive, you know how it usually goes: "comment to enter, I'll pick a winner tomorrow." And then... you just have to trust that person picked fairly. No proof, no way to check, just their word.
I wanted to fix that, so I built Hive Raffle — a free tool that uses the Hive blockchain itself to pick a winner, in a way that's mathematically impossible to fake, and that anyone can double-check afterwards.
Even a well-meaning organizer has a problem: if they pick the winner using something like a random number generator on their own computer, they could technically run it several times until they get a result they like — or people will simply assume they might have. There's no way to prove otherwise.
Hive Raffle solves this with something called a commit-reveal scheme. It sounds technical, but the idea is simple:
Since the block is announced before it exists, and the result depends entirely on it, there's no way to game the outcome — not by the organizer, and not by a participant trying to time their entry.
1. Configure the raffle. Enter the author and permlink of your post. Hive Raffle suggests a block roughly one hour in the future — enough time for people to see the announcement.
2. Announce it. Copy the text Hive Raffle generates (something like "This raffle will be resolved using Hive block #109574771") and post it publicly, for example as a comment on your own post. This is the "commit" step — you're locking in your promise before anyone knows the outcome.
3. Wait for the block. Blocks arrive roughly every 3 seconds, so an hour is usually plenty of margin.
4. Draw. Once the target block exists, hit "Draw now." Hive Raffle fetches the block, hashes its ID, and picks a winner from the list of everyone who commented on your post.
5. Anyone can verify it. This is the part I care about most. Switch to the "Verify raffle" tab, enter the same author, permlink and block number, and the tool recalculates everything from scratch, completely independently. If it matches the announced winner, the raffle was legitimate — no trust required.
You can try this right now with a real example I used while testing the tool: post by 
Two extra rules you can turn on when configuring a raffle:
Both are optional, and both are also checked during verification, so anyone reproducing the raffle gets the exact same participant list.
It's a small, no-backend, no-signup web page — just plain HTML/CSS/JavaScript talking directly to the public Hive API. No account needed to use it, whether you're running a raffle or just checking one.
If you run a giveaway with it, I'd love to see it — drop a comment below if you hit a bug or have an idea for a new filter.
