The best free open source tools: Data & analytics (2026)

The open source backend closest to Supabase: user accounts, a PostgreSQL database, files, functions, email, SMS and hosting for your site in one console. Free and unlimited on your own server, or on their free cloud to get started.

Replaces:Supabase,FirebaseSaves €22/month

A complete backend in a single file: SQLite database, user accounts, files, realtime and an admin dashboard. You run it on your server and get the equivalent of Supabase or Firebase, with no subscription.

Replaces:Supabase,Firebase,AirtableSaves €22/month

Your own Vercel on a €5 VPS: you connect a Git repo, Dokploy builds, deploys, sets up HTTPS, manages databases and backups. As many apps as you want, no Pro plan.

Replaces:Vercel Pro,Netlify Pro,Heroku,RailwaySaves €18/month

Your website statistics, at home: visitors, sources, pages, goals, on one readable screen. No cookies, no banner, no data sent to Google.

Replaces:Fathom,Simple Analytics,Google AnalyticsSaves €13/month

The open source SEO tool that does the job of Semrush and Ahrefs: keyword research, backlinks, rank tracking, site audit, visibility in AI answers. The software is free and self-hosted; the SEO data is pay as you go, a few cents per request, no subscription.

Replaces:Semrush,AhrefsSaves €134/month

The SEO crawler that combs through your site: titles, meta, broken links, redirects, JavaScript rendering, unlimited exports. What Screaming Frog does, on your machine, without the yearly licence.

Replaces:Screaming Frog SEO SpiderSaves €22/month

Turns any website into clean Markdown for Claude and your AI agents: a page, a whole site or a web search, through an API or MCP. Free with no page limit on your own machine.

Replaces:Context.devSaves €18/month

Turns any website into clean data, with no code: you click on what you want to collect, or describe it in one sentence, and a robot fetches it for you, on a schedule if you want. Free with no page limit on your own machine.

Replaces:ScrapingBeeSaves €17/month

The open source sign in server that replaces Auth0: a login page in your colours, sign in with Google and about a hundred others, two factor authentication, enterprise SSO. Your user accounts stay on your server, with no bill that grows with them.

Replaces:Auth0Saves €31/month