Free Online Developer Tools
11 free browser-based developer tools — no sign-up, no server uploads, all processing happens in your browser.
Regex Tester
Test and debug regular expressions with real-time matching, highlighting, and replacement preview
JWT Decoder
Decode and inspect JSON Web Tokens — view header, payload claims, expiration status, and signature
Diff Checker
Compare two texts and find differences with unified and side-by-side views
SQL Formatter & Beautifier
Format, beautify, and minify SQL queries with keyword casing and custom indentation
HTML Beautifier & Formatter
Beautify, format, and minify HTML with proper indentation and void element handling
XML Formatter & Beautifier
Format, beautify, and minify XML with proper indentation, comment handling, and attribute sorting
JavaScript Minifier & Beautifier
Minify and beautify JavaScript with safe string, template literal, and regex preservation
Cron Expression Parser
Parse cron expressions into human-readable schedules with next run times and syntax reference
YAML Formatter & Beautifier
Format, beautify, minify, and sort YAML with proper indentation for Kubernetes, Docker, and config files
TOML Formatter & Validator
Format, beautify, minify, sort, and validate TOML files for Cargo.toml, pyproject.toml, and configs
IP Address Lookup & Subnet Calculator
Find your public IP with geolocation, look up any IP address, and calculate subnets with CIDR notation