Regex Tester

Regular expressions (regex) are powerful pattern-matching sequences used to search, validate, and transform text. They are supported in virtually every programming language and are a fundamental tool for tasks like form validation (emails, phone numbers, URLs), log parsing, data extraction, and find-and-replace operations in codebases.

A regex pattern consists of literal characters combined with special metacharacters that define rules: dots match any character, brackets define character classes, quantifiers specify repetition, and anchors pin matches to positions in the string. Mastering these building blocks lets you express complex text patterns in a single concise expression.

This tester provides instant visual feedback as you build your pattern, highlighting every match in your test string and displaying capture groups in a structured results panel. It supports all JavaScript regex flags and includes a replace mode, making it the fastest way to develop and debug regular expressions without switching between your editor and documentation.