Not a sponsored list, not tools I've been paid to mention. Just the things I actually use regularly that happen to be free.
Cloudflare
Already wrote a whole post about this but it deserves the top spot here too. DNS management, DDoS protection, SSL, CDN, tunnels — all free. The amount of infrastructure value in the free tier is genuinely difficult to overstate. Everything I host goes through Cloudflare.
Pterodactyl
Open source game server management panel. Powers the server host I work at. Free to self-host, actively maintained, excellent API, Docker-based isolation. If you're hosting game servers for yourself or others, there's nothing better in the free space.
AdGuard Home
Network-wide ad and tracker blocking, self-hosted in Docker. Once it's running you basically never think about it — ads just stop appearing across every device on the network including ones that can't run extensions. Completely free, open source.
Vaultwarden
Self-hosted password manager that's compatible with the Bitwarden apps. All the polish of Bitwarden's clients with your data living on your own server. Free to run, open source. Password managers are non-negotiable security infrastructure and this is the best self-hosted option.
VS Code
Still the best general-purpose editor for most things. The extension ecosystem is unmatched. rust-analyzer for Rust, the Next.js/TypeScript support, the Git integration — all excellent. Free, cross-platform, constantly improving.
GitHub
Free for public repos and generous for private ones. Version control, CI/CD via Actions, issue tracking. The free tier covers everything I need for personal projects and most of what I need for the server host I work at. There's no practical reason not to have everything in Git and GitHub is the obvious place to put it.
Let's Encrypt / Certbot
Free SSL certificates, automatically renewed. Before Let's Encrypt, SSL certificates cost money and required manual renewal. Now it's one command and it's free forever. This changed the web significantly and it's still kind of remarkable that it exists.
Hetzner
Technically not free — but the cheapest decent VPS provider I've found. A small VPS starts at about £3-4 a month, the network is fast, and reliability has been solid. Not free but close enough to mention alongside the rest.