Souim shows how busy Lyon's public pools are right now, and whether it's quieter than usual. Free, ad-free and made for mobile.
Why Souim?
I swim for fun, and too often I arrived at the pool to find it full, every lane busy, or the door closed for a "technical problem".
In March 2025, Souim was just a personal tool to track how busy the pools were. It grew into a real product, used by swimmers in Lyon, with no commercial goal.
What it does
Souim answers one simple question: is now a good time to go swimming?
For each public pool in Lyon, it shows in one place:
- how many people are swimming right now
- the opening hours for the current season
- unexpected closures
- the pools, lanes and services available
- how to get there by public transport or Vélo'v bike share
A number like "12 swimmers" doesn't mean much on its own. So Souim compares it with what is normal for that time and day, and gives a clear answer, like "quieter than usual, go now".
It's free, has no ads, and is designed for mobile first.
How it works
- Live data. Souim collects the attendance numbers published online throughout the day and keeps their history, so today can be compared with past days.
- A smart "is it busy?" answer. Each pool is compared only with itself: same time, same day of the week. 12 swimmers is busy in a small pool and almost empty in a big one.
- AI to read closure notices. Closures are announced as free text, like "the pool will close early at 6 pm". An AI model turns these sentences into exact dates and times, and the result is checked against the database.
- Open or closed, no guessing. Souim takes seasonal hours, unexpected closures and evening sessions into account to tell you whether a pool is open right now.
Built with: Next.js 16, React 19, TypeScript, Tailwind CSS, shadcn/ui, PostgreSQL (Supabase) with Drizzle, the Vercel AI SDK, MapLibre, Vitest, and Vercel for hosting.