I Built 35+ Free Browser Tools as a Solo Dev - Here's How

I Built 35+ Free Browser Tools as a Solo Dev I've been building ToolsOnFire - a collection of 35+ free online tools. Video converters, AI voice separation, a sticker creator, markdown converter, and more. I'm a solo developer from the UK based in Norway. No team, no funding. Just a frustration with paying subscriptions for simple tasks, so I built free alternatives. * The Stack * Next.js 14 (App Router) with TypeScript - Firebase for auth and database Stripe for premium tiers Vercel for hosting The Key Decision: Process in the Browser Most of my tools process files entirely in the user's browser rather than on a server. My Video to Gif Converter and Video to audio converter use FFmpeg.wasm - a WebAssembly port of FFmpeg. This means files never leave the user's device. No uploads, no privacy concerns, and I don't pay for server compute. The trade-off is browser memory limits. I had to add device detection to cap file sizes on mobile and optimise how large files are handled. * AI-Powered