A collection of practical tools built for developers — test regular expressions with live match highlighting, compare text differences side-by-side, generate UUIDs, and count characters against platform limits.
Compare two blocks of text and highlight the differences.
Test regular expressions against sample text with live match highlighting.
Generate one or many UUIDs (v4) instantly.
Count characters against Twitter, LinkedIn, and SMS limits.
Generate MD5, SHA-1, SHA-256, SHA-512 hashes from text.
Escape special characters for JSON strings, or unescape JSON string values.
Minify HTML by removing whitespace, comments, and optional attributes.
Format messy CSS or minify it for production.
Format and beautify JavaScript code with Prettier.
Format, beautify, and validate XML documents.
Validate YAML syntax and format errors with line numbers.
Calculate Unix file permissions using checkboxes and see the numeric value.
Check WCAG AA and AAA contrast ratios for foreground and background colours.
Look up every HTTP status code with description and usage notes.
Look up MIME types by file extension or search by keyword.
Reference for escape sequences in major programming languages.