The open-source World Cup 2026 bracket challenge you can self-host

Most prediction apps are black boxes. FriendlyBet is the opposite: every line that runs in your browser is readable, MIT-licensed, and yours to fork. Here is what that means in practice.

FriendlyBet Live is a free, open-source, privacy-first World Cup 2026 prediction pool for friends, offices and tech teams — no signup, no ads, no money, no personal data. The full source lives on GitHub under the permissive MIT license, so developers can audit exactly what the app does, contribute, or stand up a private copy of their own.

Framework-free by design

FriendlyBet is built with hand-written HTML, modern CSS and Vanilla JavaScript. There is no React, no bundler, and no build step. You can open app.js and read precisely what runs — which is both a feature for auditability and the reason the app loads instantly. It ships as an installable PWA with an offline-aware service worker.

Self-host it in about two minutes

Because it is pure static files, hosting your own instance is trivial:

1. Clone the repository from GitHub.
2. Create a free Supabase project and run the idempotent SQL migrations in /migrations.
3. Set your keys in config.js (the Supabase URL and public anon key — the anon key is meant to be public; Row-Level Security protects the data).
4. Deploy to Vercel, Netlify or GitHub Pages. There is nothing to build.

How the bracket challenge works

You predict all 12 group standings, then build the full official Round-of-32 knockout bracket through to the Final, and call the Golden Boot top scorer. The clever part: your knockout bracket is generated from your own group predictions, so it is a true test of your forecast rather than a copy of the real draw. Scoring uses a doubling progression — later, harder rounds are worth more — and runs as a deterministic, idempotent CI job, so a re-run always converges to the same answer. No cheating, no manual tallying.

Open-source bracket FAQ

Is there an open-source World Cup 2026 bracket challenge?

Yes — FriendlyBet Live, MIT-licensed and on GitHub.

What license is it under?

The permissive MIT license. Use, modify, fork and redistribute freely.

Do I need a build toolchain to run it?

No. It is static HTML/CSS/JS with no build step. Serve the folder and it works.

Can I point it at my own database?

Yes. Edit config.js with your own Supabase URL and anon key.

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