Developer Tools
A growing collection of developer tools that don't upload your code, tokens, or data. Format JSON, decode JWTs, generate UUIDs, encode base64, test regex patterns, and more. All open-web, all client-side, all free.
JSON Formatter
Format, beautify, minify, and validate JSON data instantly.
Base64 Encoder/Decoder
Encode text to Base64 or decode Base64 strings back to plain text.
URL Encoder/Decoder
Encode or decode URLs and query parameters. Handle special characters safely.
Color Converter
Convert colors between HEX, RGB, and HSL formats. Pick colors visually.
Regex Tester
Test and debug regular expressions with real-time matching, highlighting, and group extraction.
CSS Minifier
Minify CSS code to reduce file size. Remove comments, whitespace, and unnecessary characters.
HTML Minifier
Minify HTML by removing comments, whitespace, and unnecessary tags.
Unix Timestamp Converter
Convert Unix timestamps (epoch) to human-readable dates and back. Seconds or milliseconds. ISO 8601, UTC, local.
QR Code Generator
Generate QR codes for URLs, text, WiFi, and more. Download as PNG.
Markdown to HTML
Convert Markdown text to clean HTML. Live preview and copy-ready HTML output.
JWT Decoder
Decode JWT tokens online. View header, payload, claims, and expiry. 100% client-side - your token stays private.
UUID Generator
Generate UUID v4 (random) or UUID v7 (time-sortable). Bulk lists up to 1,000. Web Crypto powered.
YAML ↔ JSON Converter
Convert between YAML and JSON formats. Instant, validated, bidirectional.
Text Diff Checker
Compare two blocks of text side-by-side. See additions, removals, and changes highlighted.
CSS Gradient Generator
Design beautiful linear and radial CSS gradients with live preview. Copy-ready code.
Chmod Calculator
Calculate Linux/Unix chmod numeric and symbolic permissions with checkboxes. Common presets included.
JSON to CSV
Convert JSON arrays to CSV instantly. Flatten nested objects, choose delimiter, download as .csv file.
Cron Expression Generator
Build cron expressions with a visual editor. Get plain-English descriptions, common presets, and field reference.
Text to CSV
Convert plain text, tab-separated, space-separated, or pipe-separated data to CSV. Auto-detects delimiter.
XML to JSON Converter
Convert XML to readable JSON or JSON back to formatted XML, preserving attributes, text values, nested elements, and repeated sibling arrays.
About these tools
Built for developers who care about privacy. Pasting an API response with a bearer token into an online JSON formatter that runs on a server means that token is now logged somewhere you don't control. The tools in this category run entirely in your browser. Open your network tab and watch: zero requests. JSON formatting, JWT decoding, UUID generation, hash calculation, and regex testing all happen via native JavaScript and Web Crypto APIs without sending anything to a backend.