Free Online Developer Tools
Fast, free, and private. All tools run in your browser — no data leaves your device. No signup required.
All Tools
JSON Formatter
DeveloperFormat, validate, and minify JSON data instantly
Base64 Encoder/Decoder
DeveloperEncode and decode Base64 strings and files
JWT Decoder
DeveloperDecode and inspect JSON Web Tokens
Hash Generator
DeveloperGenerate MD5, SHA-1, SHA-256, SHA-512 hashes
Regex Tester
DeveloperTest regular expressions with live highlighting
URL Encoder/Decoder
DeveloperEncode and decode URLs and query strings
Word & Character Counter
TextCount words, characters, sentences, and reading time
Color Converter
DesignConvert between HEX, RGB, HSL color formats
Lorem Ipsum Generator
TextGenerate placeholder text for your designs
Markdown Preview
TextWrite and preview Markdown in real time
Unix Timestamp Converter
DeveloperConvert between Unix timestamps and human dates
JSON to CSV
DeveloperConvert JSON arrays to CSV and back
Diff Checker
TextCompare two texts and highlight differences
HTML Encoder
DeveloperEncode and decode HTML entities
Case Converter
TextConvert between camelCase, snake_case, kebab-case
JSON Validator
DeveloperValidate JSON with detailed error messages
UUID Generator
DeveloperGenerate UUID v4 instantly, single or bulk
SQL Formatter
DeveloperFormat and beautify SQL queries
Cron Parser
DeveloperParse cron expressions to human-readable text
Chmod Calculator
DeveloperCalculate Unix file permissions interactively
Free Developer API
DevToolBox API
18+ endpoints, no API key neededFree REST API: URL shortener, hash generator, UUID, placeholder images, random data, and more. 100k requests/day.
Why DevToolBox?
100% Client-Side
All processing happens in your browser. Your data never leaves your device.
No Signup
Just open and use. No accounts, no tracking, no nonsense.
Always Free
Core tools are free forever. No paywalls on essential features.