Developer & Data Tools
Format and validate JSON, encode Base64 and URLs, decode JWTs, test regex and convert data.
24 tools · everything runs in your browser
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JSON Formatter
Format, validate and minify JSON with exact error locations.
JSON to CSV Converter
Convert JSON arrays to CSV, and CSV back to JSON.
SQL Formatter
Format, beautify, and minify SQL queries for Postgres, MySQL, and SQLite.
Base64 Encoder & Decoder
Encode text or files to Base64, or decode Base64 back to text or a file.
JWT Decoder
Decode a JWT, see what each claim means, and verify its signature.
Regex Tester
Test regular expressions with live match and group highlighting.
JSON to YAML Converter
Convert bidirectional JSON to YAML and YAML to JSON with presets.
UUID Generator
Generate v4 and time-ordered v7 UUIDs in bulk, or inspect any UUID.
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Base64 Encoder & Decoder
Encode text or files to Base64, or decode Base64 back to text or a file.
Chmod Permissions Calculator
Interactive 3x3 Linux permissions matrix, octal sync, and command generator.
Color Contrast Checker
Check text and background colours against WCAG AA and AAA.
Color Converter
Convert any CSS colour to HEX, RGB, HSL, OKLCH and more, with shades and palettes.
Color Palette Generator
Generate 11-step Tailwind color shades with WCAG accessibility contrast.
Cron Expression Explainer
Read cron schedules in plain English and build new ones.
CSS Box Shadow Generator
Multi-layer CSS box shadows with live preview and Tailwind export.
Docker Run to Compose
Convert docker run CLI commands into docker-compose.yml files.
Glassmorphism Generator
Create modern CSS frosted glass effects with backdrop blur and border glow.
HTML Entity Encoder & Decoder
Escape or unescape HTML characters as named, decimal or hex entities.
JSON Formatter
Format, validate and minify JSON with exact error locations.
JSON to CSV Converter
Convert JSON arrays to CSV, and CSV back to JSON.
JSON to TypeScript Converter
Generate TypeScript interfaces from a JSON sample.
JSON to YAML Converter
Convert bidirectional JSON to YAML and YAML to JSON with presets.
JWT Decoder
Decode a JWT, see what each claim means, and verify its signature.
Markdown Table Generator
Build Markdown and HTML tables in a spreadsheet-style grid.
PX to REM Converter
Convert PX to REM and calculate responsive fluid clamp() typography.
Regex Builder
Build a regular expression from blocks, with live matches.
Regex Tester
Test regular expressions with live match and group highlighting.
Sample File Generator
Create test images, PDFs, CSV, JSON or video at an exact file size.
SQL Formatter
Format, beautify, and minify SQL queries for Postgres, MySQL, and SQLite.
SVG to Data URI Converter
Clean and encode SVG markup into UTF-8 and Base64 Data URIs.
URL Encoder & Decoder
Percent-encode text for URLs, or decode an encoded URL.
UUID Generator
Generate v4 and time-ordered v7 UUIDs in bulk, or inspect any UUID.
About these tools
Debugging usually means pasting something sensitive into a tool — an API response with customer records, an auth header, a production token. Doing that on a site that posts the data to its own backend is a real risk, and one that has caused genuine incidents. Every tool in this category processes input in your browser and makes no network request with it.
These cover the routine tasks that come up constantly in day-to-day work: making an unreadable JSON payload legible, checking why a token is being rejected, encoding a URL that keeps breaking, or generating identifiers for test fixtures.
Guides
Step-by-step walkthroughs for jobs these tools handle.