PickKeepersA raffle everyone can check
Watching a winner appear is one thing. Being able to check it later is another. PickKeepers locks the list in before the spin and gives every draw a link anyone can re-run.
PickKeepers for iPhone and iPad is coming soon. You can try the free web version now at sviewstudios.com/pickkeepers/app/. Lock-in before the spin, proof links, the QR lobby and the one-device room demo arrive with the next PickKeepers version.
Two promises, both checkable
Locked in before the spin
Before the countdown, the host's list is sealed. If anyone adds, removes or edits an entry afterwards, the seal no longer matches and the check says so. No quiet re-roll.
Anyone can re-run it
Every draw has a proof link. Open it, press Check this draw, and your own browser works out the result again from the same list. If it matches, you have checked it yourself.
What a check does and does not tell you
- It shows that the winner follows from the list and the draw code, and that the list is the one that was locked in before the spin.
- It does not show that the list itself was honest. If a host leaves a name off the list, no check can see that. Keep the list on a screen where the room can read it.
- By default the proof page hides names. Entries appear as numbers unless the host chooses to show names, which suits classrooms and privacy-minded groups.
For the curious: how the check works
Each draw gets a random draw code. The winner is calculated from that code and the list by a fixed, public recipe (a 32-bit hash feeding a small random number generator), so the same inputs always give the same winner on any device. Before the spin the list is sealed with a SHA-256 hash that includes a secret salt, and the salt is revealed when the winner is shown, so the check can confirm that the list has not changed. Nothing in the winner calculation uses the clock or the network.
You can try it yourself on the check page: it runs the same code as the app, inside your browser, and sends nothing anywhere.
Try it in three steps
- Run a draw in the web app or the iPhone app.
- Share the proof link with the room, or save it for your records.
- Anyone can open it and press Check this draw.
Questions
What does a fair raffle draw mean here?
That the winner follows from the list and the draw code by a fixed public recipe, and that the list was locked in before the spin so it could not be changed afterwards.
Can the host cheat?
The lock-in stops the list changing after the countdown starts, and the check shows if it did. It cannot prove that the list itself was complete, so keep the list visible to the room.
Do I have to share names on the proof page?
No. Names are hidden by default and entries show as numbers. The host can choose to show them.
Is a draw code a guarantee against rigging?
It makes rigging after the fact detectable, not impossible before the fact. That is why the list should be shown to the room first.
Does the check send my list anywhere?
No. The check page runs in your browser and nothing is uploaded.
What PickKeepers is not
- Not a scoreboard, game clock, bracket, quiz or flashcard app. For those, see ScoreKeepers (a shared live scoreboard), ClockKeepers (a game clock and timers), BracketKeepers (tournament brackets), QuizKeepers (classroom quizzes), FlashKeepers (flashcards).
- Not a social giveaway tool. It does not log in to Instagram, TikTok or any account, and it does not pull comments. You bring the list, or people join the room.
- Not an account system. Hosts and participants need no sign-up, and the free version has no ads.
- Not a replacement for local raffle or lottery rules. If your raffle needs a license or a reporting step, that part is yours; PickKeepers only makes the draw itself easy to watch and check.