Free Online Regex Tester

About Regex Tester

Regular expressions (regex) are powerful patterns used to search, match, and manipulate text. Our Regex Tester lets you write a pattern, choose flags, and instantly see all matches highlighted directly in your test string. The match list shows each match with its position index.

How to Use

• Enter a regex pattern in the pattern field (no surrounding slashes needed).
• Select flags: g (global) for all matches, i for case-insensitive, m for multiline.
• Paste your test string and click Test.
• Matches are highlighted in the output. The match list shows each match and its index.

Regex Tips

Common patterns include \d+ for numbers, \w+ for words, [a-z]+ for lowercase letters, ^ for start of line, and $ for end of line. Use parentheses for groups and | for alternation. Backslashes must be escaped in certain contexts.