Developer Tools
Work with the numbers and formats behind the code — free developer tools that run entirely in your browser, with nothing uploaded. All 7 tools below are free with no login.
- Number Base ConverterEvery base at once — edit any field, the rest follow. Big numbers stay exact.runs entirely in your browser
- Font File ViewerPreview TTF, OTF, WOFF, or WOFF2 without installing it. Inspect TTF, OTF, and WOFF metadata and glyphs.runs entirely in your browser
- Regex TesterWatch the matches light up, then see the same pattern drawn as track you can read.runs entirely in your browser
- JWT DecoderRead every claim, check the expiry clock, and verify HMAC signatures in your browser.runs entirely in your browser
- Cryptographic Key GeneratorGenerate exact-length AES and HMAC keys, salts, IVs, nonces, or random secret bytes on your device.runs entirely in your browser
- PX to REM Converterpx ⇄ rem at any root size — one value, or your whole stylesheet.runs entirely in your browser
- Line Height CalculatorThe right leading for any font size — unitless, px, em, or percent.runs entirely in your browser