Regex tester
Build a regular expression and see what it matches as you type.
Matches: 0
Your pattern and text stay in your browser. Nothing is uploaded.
How to use this tool
- Type a regular expression in the pattern box.
- Choose any flags you need.
- Type or paste test text. Matches highlight as you go and the count updates live.
About the flags
Global finds every match instead of stopping at the first. Ignore case treats upper and lower case as the same. Multiline lets the start and end anchors match at each line break rather than only the whole text.
A real example
You have a wall of log text and need every email address in it. A pattern for word, at sign, word, dot, word with the global flag highlights them all at once, so you can confirm your expression works before using it in code.
Common questions
Why does it say invalid pattern?
The expression has a syntax error, often an unclosed bracket or group. Fix the highlighted message and the matches return.
Which regex flavor is this?
It uses the browser's built-in JavaScript engine, so the syntax matches what you would use in JavaScript code.