Developer Tools

Diffs, regular expressions, hashing, formatting, and other coding helpers.

Calculate CRC32 or Adler-32 checksums for UTF-8 text locally in your browser.

Escape text into an ECMAScript string literal, or decode a JavaScript string literal back to plain text.

Test a JavaScript regular expression against sample text: see every match, its position, capture groups, and a replacement preview.

Compare two blocks of text line by line and get a unified diff with added, removed, and unchanged line counts.