Developer tools

All tools 20

JSON, CSV, Base64, URL, JWT, hashes, UUIDs, regex, cron, colours, networking and permissions.

• JSON Formatter & Validator

  Check JSON, see the exact line and column of any error, and format or minify it, all inside your browser.

• QR Code Generator

  Make QR codes for links, text, Wi-Fi and contacts in your browser, and download them as SVG or PNG.

• Regex Tester

  Test a regular expression with live highlighting, groups, a plain-English explanation and ready-made patterns.

• Diff Checker

  Compare two texts or code files line by line, inline or side by side, with changed words highlighted.

• Base64 Encoder & Decoder

  Encode text or files to Base64 and decode it back, with UTF-8 and URL-safe support, entirely in your browser.

• Password Generator

  Make strong random passwords on your device with secure randomness and an exact entropy figure.

• UUID Generator

  Generate version 7 or version 4 UUIDs in bulk, and check the version and time of any UUID.

• Unix Timestamp Converter

  Convert Unix timestamps to dates in IST and UTC, and dates back to timestamps, in seconds or milliseconds.

• Bandwidth Calculator

  Estimate how long a download or upload takes at your speed, and the speed you need to finish in time.

• chmod Calculator

  Convert Unix file permissions between octal and symbolic forms, with special bits and the chmod command.

• Color Contrast Checker

  Check text and interface colours against WCAG 2.2 AA and AAA, and get the nearest colour that passes.

• Color Converter

  Convert colours between HEX, RGB, HSL and OKLCH, with copy-ready CSS and a readable text colour.

• Cron Expression Explainer

  See what a cron schedule means in plain English and its next 10 run times in IST and UTC.

• CSV to JSON Converter

  Convert CSV or spreadsheet exports to JSON in your browser, with quoted fields, delimiters and types handled.

• Dice Roller

  Roll any dice fairly, such as 2d6 or d20+5, and see the exact chance of every total.

• Hash Generator

  Compute SHA-256, SHA-384, SHA-512 and SHA-1 hashes of text or files, and check a download’s checksum.

• IP Subnet Calculator

  Work out an IPv4 subnet’s network, broadcast, host range and mask, and split it into smaller subnets.

• JWT Decoder

  Decode a JSON Web Token in your browser and see its claims, algorithm and expiry in IST and UTC.

• Markdown Previewer

  Write Markdown and see it formatted instantly, with clean HTML to copy and nothing ever run or uploaded.

• URL Encoder & Decoder

  Percent-encode text for links and query strings or decode it back, with the right mode explained.