Regex Tester
Developer Tools0 Matches
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How to use this regex tester
- Type your pattern and flags (like gmi).
- Paste or type test text.
- Matches highlight instantly, with a live match count.
What is a regular expression?
A regex is a pattern used to match character combinations in strings, widely used for validation, search-and-replace, and parsing text.
What do the flags g, m, and i mean?
"g" finds all matches instead of just the first, "i" makes matching case-insensitive, and "m" makes ^ and $ match the start/end of each line instead of the whole string.
Why does my pattern show an error?
This usually means invalid regex syntax, an unclosed bracket, an invalid escape sequence, or unbalanced parentheses are common causes.