Developer Tools — 20+ free online developer utilities
A privacy-first collection of developer tools that run 100% in your
browser. Nothing is uploaded — all processing happens locally and the
app works fully offline as a PWA. Free to use, no sign-up required.
Available tools
- JSON Formatter & Validator — format, validate, beautify and minify JSON.
- YAML Formatter & Converter — beautify YAML and convert YAML ↔ JSON.
- XML Formatter & Viewer — prettify, indent and validate XML.
- CSV Viewer & Converter — view CSV as a table and convert CSV ↔ JSON.
- SQL Formatter — format and prettify SQL queries.
- HTML Formatter — format, indent and beautify HTML.
- CSS Formatter — format and beautify CSS stylesheets.
- Regex Tester — test and debug regular expressions with live matches.
- Smart Diff — compare two texts, JSON, XML or code side by side.
- String Utilities — change case, reverse, trim and count text.
- Base64 Encoder & Decoder — encode and decode Base64.
- JWT Decoder & Debugger — decode and inspect JSON Web Tokens.
- Hash Generator — generate MD5, SHA-1, SHA-256 and SHA-512 hashes.
- URL Encoder & Decoder — percent-encode and decode URLs.
- Number Base Converter — convert between hex, decimal, binary and octal.
- Unix Timestamp Converter — convert epoch time to dates and back.
- Cron Expression Parser — parse and explain crontab schedules.
- UUID Generator — generate UUID v4 and v7 identifiers.
- Lorem Ipsum Generator — generate placeholder text.
- Fake Data Generator — generate realistic mock names, emails and JSON.
- Color Picker & Converter — pick colors and convert HEX ↔ RGB ↔ HSL.