Free data and developer tools.

Format, minify or validate JSON in your browser, with the exact position of any syntax error.

Convert CSV to a JSON array of objects, using the first row as keys. Handles quoted fields, commas and line breaks inside quotes.

Turn a JSON array of objects into CSV for Excel or Google Sheets, with correct quoting.

Encode text to Base64 or decode Base64 back to text, UTF-8 safe, including URL-safe Base64.

Percent-encode text for use in a URL query string, or decode %XX sequences back to text.

Escape text so it shows literally in HTML (& < > " '), or turn entities like &amp;eacute; back into characters.

Decode a JSON Web Token to read its header and payload, with expiry times shown as dates. Does not verify the signature.

Compute SHA-1, SHA-256, SHA-384 or SHA-512 hashes of text in your browser, as hex.

Generate random version 4 UUIDs, one or many at a time, using the browser's cryptographic random generator.

Convert a Unix timestamp (seconds or milliseconds since 1970) to a date in UTC and ISO 8601, or a date back to a timestamp.

Convert whole numbers between binary, octal, decimal and hexadecimal, of any size.

Work out X% of a number, what percentage one number is of another, and the percentage change from one value to another.

Compound annual growth rate from a start value, an end value and the number of years between them.

Count words, characters (with and without spaces), lines, UTF-8 bytes and estimated reading time.

Convert text to UPPER, lower, Title Case, camelCase, PascalCase, snake_case, kebab-case or CONSTANT_CASE.

Test a JavaScript regular expression against text and see every match with its position and capture groups.

Convert a colour between HEX, RGB and HSL, and check its contrast ratio against white and black text.