Home
Tom Utilities

Regex Cheat Sheet

Developer Utilities

A quick reference of regular expression syntax with character classes, quantifiers, anchors, groups, lookaround and escapes.

How to use

Using the cheat sheet

Search for a token or a description to filter the table, then use the pattern directly in JavaScript, Python or any engine that follows the common syntax.

  1. Search for a pattern or keyword.
  2. Read the description.
  3. Copy the token into your expression.

Frequently asked questions

Which regex flavour is this?

The common Perl-compatible subset supported by JavaScript, Python, Java and most other engines.

Does the dot match newlines?

By default it does not. Enable the s (dotAll) flag in JavaScript or re.DOTALL in Python if you need it to.

Related tools

Regex Tester Test regular expressions against sample text and inspect every match and capture group. Word & Character Counter Count characters, words, lines, sentences and paragraphs, with reading time and UTF-8 size. UUID / GUID Generator Generate random version 4 UUIDs and copy them one by one or in bulk. Hash Generator Compute MD5, SHA-1, SHA-256 and SHA-512 digests of any text. Timestamp Converter Convert between Unix timestamps, ISO 8601 and human readable local dates. Text Compare / Diff Compare two blocks of text and see line level additions, removals and changes.