Tools4Free is a growing library of free online tools: percentage and BMI calculators, unit and currency converters, QR and password generators, and more. Every tool runs entirely in the visitor’s browser. No account, no ads, no tracking, no paywall.

The idea is boring on purpose. Most tool sites bury a simple calculator under three ad units and a newsletter popup. Tools4Free does the opposite: fast, clean, and available in several languages, so the answer you came for is the first thing you see.

Built with Next.js 15 on Vercel, statically generated so each tool page loads instantly and works offline once cached. The catalog spans roughly 1,800 pages, mostly programmatic long tail conversions and calculations, with a shared component shell so a new tool is a few lines of config, not a new app.