Free Online Developer Tools
Format, validate and transform your data instantly — no signup required, everything runs in your browser.
JSON Formatter
Format, validate and minify JSON instantly.
XML Formatter
Format, validate and minify XML with syntax highlighting.
HTML Formatter
Beautify or minify HTML code in one click.
HTML Viewer
Render and preview HTML directly in your browser.
Image to PDF
Convert images to a PDF file instantly.
Regex Tester
Test regular expressions with real-time match highlighting.
Cron Builder
Build cron expressions and get natural language descriptions.
JWT Decoder
Decode and inspect JWT tokens — header, payload and claims instantly.
JS Formatter
Beautify or minify JavaScript code instantly in your browser.
Diff Checker
Compare two texts, code snippets or JSON files and see what changed.
Hash Generator
Compute MD5, SHA-256, SHA-512 hashes and generate UUID v4 / random tokens.
cURL to Code
Convert cURL commands to Python, JavaScript, Java or C# code instantly.
QR Code Generator
Generate QR codes for URLs, text, email or phone numbers. Download as PNG or SVG.
Image Converter
Convert images between PNG, JPEG, WebP and BMP formats in your browser.
PDF Tools
Merge, split and reorder PDF files entirely in your browser — no upload needed.
Base64 Encoder / Decoder
Encode text or files to Base64 and decode Base64 strings instantly in your browser.
URL Encoder / Decoder
Percent-encode URLs and query strings, or decode %XX sequences back to readable text.
Timestamp Converter
Convert Unix timestamps to human-readable dates and dates back to epoch time.
JSON ↔ CSV Converter
Convert JSON arrays to CSV and CSV back to JSON. Download the result as a file.
CSS Formatter
Beautify messy CSS with consistent indentation, or minify it to reduce file size.
Markdown to HTML
Live Markdown editor with split-pane HTML preview and copy output.
Password Generator
Generate strong, random passwords with configurable length and character sets.
Color Converter
Convert color codes between HEX, RGB and HSL. Pick a color visually or type any format.
About Developer Tools
Developer Tools is a free, privacy-friendly collection of browser-based utilities built for developers. All processing happens locally in your browser — your data is never sent to a server.
Whether you need to format a JSON response, validate XML, preview an HTML snippet, test a regular expression or convert an image to PDF, you will find a fast and simple tool here.
Every tool is designed to be instant and distraction-free: no ads, no login, no file size limits. Tools include a JSON Formatter, HTML Viewer, JWT Decoder, Regex Tester, Cron Builder, Diff Checker, Hash Generator and more. New tools are added regularly based on developer feedback.