Free Online Developer Tools
12 free tools — essential tools for developers — format, encode, decode, and test
Essential utilities for web developers — format JSON, encode and decode Base64 and URLs, test regular expressions, decode JWTs, minify CSS and JavaScript, beautify HTML, compare code, and pick colors. Every tool runs client-side with no server dependencies, making them safe for working with API keys, tokens, and sensitive data. Whether you're debugging an API response, optimizing production assets, or prototyping a color scheme, these tools eliminate the need for installing CLI utilities or desktop applications.
All Developer Tools (12)
JSON Formatter
Format, validate, and beautify JSON data with syntax highlighting, error detection, and tree view
PopularBase64 Encoder/Decoder
Encode and decode text or binary data in Base64 format for embedding images, APIs, and data transfer
PopularRegex Tester
Test, debug, and validate regular expressions with real-time matching, group highlighting, and flag support
PopularURL Encoder/Decoder
Encode and decode URLs and query parameters for safe transmission in web applications and APIs
HTML Encoder/Decoder
Encode and decode HTML entities, special characters, and Unicode symbols for safe web content
JWT Decoder
Decode and inspect JSON Web Token headers, payloads, and signatures with expiration time validation
Markdown Previewer
Write Markdown in a live editor and preview the rendered HTML output with full syntax support
Color Picker
Pick any color from a visual palette and get instant HEX, RGB, and HSL values ready to copy
CSS Minifier
Minify CSS code to reduce file size and improve page load performance with compression statistics
JavaScript Minifier
Minify and compress JavaScript code for production deployment with size reduction reporting
HTML Beautifier
Format and auto-indent messy HTML code into clean, readable markup with configurable indentation
Code Diff Checker
Compare two code snippets side by side with syntax-aware diffing and color-coded change highlighting
Why Use itoolz for Developer Tools?
Safe for sensitive data — nothing leaves your browser
No installation — replaces CLI tools you'd normally install
Real-time validation and error detection
Syntax highlighting and tree views for complex data
Production-ready minified output for CSS and JavaScript
Supports all common encoding and decoding formats