Utility Tools

Practical tools for everyday calculations and conversions

Our utility tools are designed to make everyday tasks faster and easier. From converting units and counting text to generating QR codes and debugging JWT tokens — each tool runs entirely in your browser with zero data uploads. Built for speed, privacy, and simplicity.

Pick the right tool

Three of the calculators here have known precision tradeoffs worth flagging. The Unit Converter uses double-precision floats, which means very large temperature deltas (above ~1015 K) lose meaningful digits — fine for everyday use, not for physics homework on extremes. The BMI Calculator implements the standard kg / m² formula but BMI is a population statistic, not a personal diagnosis (it can't distinguish 80 kg of muscle from 80 kg of fat — see our deep-dive on body composition). The D-Day Calculator ignores DST and leap-second adjustments by design — it works in calendar days, not elapsed seconds.

The developer-oriented tools (JWT Debugger, JSON/YAML Converter, Kubeconfig Manager) all run client-side, so you can paste tokens or kubeconfigs without them touching a server. That matters: many similar tools online send your input to a backend "for processing." If you're inspecting a JWT that contains a session ID, that's a real leak. See JWT storage tradeoffs and the kubeconfig context guide for context.

Looking for image work? See the Image tools index. Looking for randomizers and decision aids? See Fun & Random.