Developer Tools

20 free tools · runs entirely in your browser · no signup needed

JSON Formatter & Validator Format, minify and validate JSON with syntax highlighting and error detection. XML Formatter & Validator Format, validate, and pretty-print XML with proper indentation and error detection. JSON ↔ CSV Converter Convert JSON arrays to CSV and CSV tables back to JSON — instantly in your browser. Regex Tester Test regular expressions with live match highlighting, flags, and captured groups. JWT Decoder Decode a JSON Web Token to inspect its header, payload, and signature instantly. Hex / Binary / Decimal Converter Convert numbers instantly between decimal, hexadecimal, binary, and octal formats. Color Code Converter Convert colors between HEX, RGB, HSL, and CMYK formats with a live color preview. CSS Gradient Generator Visually build linear and radial CSS gradients with a live preview and instant code output. CSS Box Shadow Generator Adjust sliders to design a CSS box-shadow visually, with live preview and instant code. CSS Flexbox Generator Visually build Flexbox layouts with live preview and copy-ready CSS for container and items. CSS Minifier & Beautifier Minify CSS to reduce file size, or beautify minified CSS back into readable, indented code. HTML Formatter & Beautifier Clean up messy or minified HTML with proper indentation and readable structure. HTML Minifier Compress HTML by removing unnecessary whitespace and comments to reduce page weight. JavaScript Minifier & Beautifier Minify JavaScript for production, or beautify minified/compressed JS back into readable code. Favicon Generator Upload an image and generate all favicon sizes plus the HTML tags to add to your site. Markdown Previewer Write or paste Markdown and see the live-rendered HTML preview side by side. .gitignore Generator Generate a .gitignore file tailored to your language, framework, or editor in one click. HTTP Status Codes Look up any HTTP status code with its meaning, description, and use cases. Cron Expression Explainer Translate cron expressions into plain English and see the next scheduled run times. User Agent Parser Parse any User-Agent string to identify the browser, operating system, and device type.

Free Online Developer Tools

All 20 developer tools on YoTools run entirely in your browser — no data is ever sent to a server. Format and validate JSON or XML, decode JWTs, test regular expressions with live highlighting, look up HTTP status codes, build CSS gradients, box shadows, and flexbox layouts visually, minify or beautify CSS/HTML/JavaScript, generate favicons and .gitignore files, preview Markdown, convert number bases and color codes, and more.