Free Online Tools

Fast, private, no sign-up. Calculators, converters and generators that run right in your browser — and a free JSON API for every tool, so AI agents can use them too.

Time

Age Calculator

Calculate exact age in years, months, days from a birth date.

Health

BMI Calculator

Body Mass Index calculator with metric & imperial units.

Math

Percentage Calculator

Percentage of a number, percent change, increase/decrease.

Security

Password Generator

Strong, random passwords generated locally in your browser.

Text

Word Counter

Count words, characters, sentences and reading time.

Generators

QR Code Generator

Create QR codes for links, text, Wi-Fi and more.

Converters

Length Converter

Convert meters, feet, inches, miles, km and more.

About toolhub

toolhub is a growing collection of free online utilities — calculators, converters and generators. Everything runs locally in your browser, so your data never leaves your device. No accounts, no tracking-heavy ads, no clutter.

Why use our tools?

Private by design — all calculations happen in your browser, nothing is uploaded.
No sign-up — every tool is free and instantly usable.
Fast & lightweight — pages load in a blink, even on slow connections.
AI-ready — each tool has a free JSON API and copy-paste prompts for AI assistants.
Mobile friendly — works perfectly on phones, tablets and desktops.

Support us

These tools are free to use. If they save you time, tap the Tip Us button (bottom right) to buy us a coffee — it helps keep new tools coming.