Regex Tester

Test JavaScript regular expressions with live match highlighting, flags, and match details.

Regular Expression Pattern

//g

Flags:

g(global)i(case insensitive)m(multiline)s(dot all)

Test String

When to use it

Validate a pattern before using it in frontend validation, scripts, or log parsing.
Check how JavaScript regex flags change matching behavior.
Debug escaping problems before moving a pattern into source code.

Examples

Test an email-like validation pattern against valid and invalid samples.
Use the global flag to confirm every match in a log line.
Check whether a pattern needs multiline mode before using it on pasted text.

Limitations

This tester uses JavaScript regular expression behavior. Regex engines differ, so verify patterns again if you move them to another language, database, or CLI tool.

Related paths

Regex cheatsheet

Look up syntax while building a pattern.

Base64 tool

Decode text before matching against it.

Diff Viewer

Compare pattern output or transformed text.