Show HN: A free, no-login random decision toolkit (roulette, teams, order, dice)

Posted by hejinhui 2 hours ago

12Original

Hi HN — I built a small browser-only “random decision” toolkit for classrooms/events/office raffles.

Link: https://roulette-tool.online/

What it does: pick winners from a pasted list, spin a roulette, decide an order, split teams, roll dice, flip a coin.

Key details:

Uses the browser’s cryptographic RNG (Web Crypto) for fairness

No login / no email — data is processed locally on the device

Mobile-first UI, plus fullscreen mode for projector use

One-tap copy of results

I’d love feedback on: (1) usability on mobile, (2) any confusing wording, and (3) feature requests (e.g., weighting, history, shareable links).

Note: the UI is currently Japanese-first; if that’s a blocker, tell me and I’ll prioritize an English toggle.

Comments

Comment by hejinhui 2 hours ago

Extra technical detail: randomness comes from Web Crypto (crypto.getRandomValues). I avoided server-side generation so the draw can work offline-ish and doesn’t require sending participant lists to a backend.

If anyone wants it, I can add a short “how randomness works” page + a reproducibility note.

Comment by vansxxx 2 hours ago

Big fan of the 'no login / local-only' philosophy. Too many simple tools demand an email just to spin a wheel. Regarding your feature request for Shareable Links: Since you want to keep it backend-free, you could just serialize the list/settings (JSON) and base64 encode it into the URL hash or query parameters. That way, I can configure a 'Daily Standup Order' list, bookmark the URL, and share it with my team, all while maintaining your zero-database architecture.