//gi
2 matches
“hello@toolora.com” at index 12
Group 1: hello
Group 2: toolora.com
“support@example.org” at index 33
Group 1: support
Group 2: example.org
How to use
01
Enter your pattern
Type the expression between the slashes shown in the Pattern field; the tool adds the delimiters for you. Syntax errors surface immediately in a red alert.
02
Toggle the flags
Check global to find every match instead of the first, case-insensitive to ignore casing, multiline so ^ and $ work per line, and dotAll to let the dot cross newlines.
03
Paste realistic test text
Put genuine samples in the Test string box, including lines that shouldn't match. Each result shows the matched text, its index, and every capture group.
Why Regex Tester
- Live results as you type, no Run button needed.
- Captures groups so you can see what each part matches.
- 100% client-side. Your text never leaves your browser.
Common questions
Which engine runs the patterns here?
The browser's native RegExp engine, which makes it a true javascript regex tester. Most syntax carries over to Python, Go, or Java, but details like lookbehind support and named groups vary, so confirm in your target language before shipping.
Is this a regex match tester or just a syntax validator?
Both. Invalid patterns trigger an error message from the engine, and valid ones are executed against your test string with every match, offset, and capture group listed below.
Why does my pattern grab more text than I expected?
Usually a greedy quantifier. Constructs like .+ expand as far as they can, so tighten the character class, add anchors, or switch to the lazy form .+? and watch the match list shrink.
Can I match across multiple lines of log output?
Yes. Paste the whole block into the test string, then enable multiline if you anchor per line, or dotAll if your pattern needs the dot to walk over newline characters.
What does the index shown next to each match mean?
It's the zero-based character offset where the match starts in your test string. That number maps directly to what String.prototype.slice or substring would use in code.
Does my sample text get sent anywhere?
No. Pattern matching executes locally in your browser, so proprietary logs or user data in the test string never touch a server.
Do zero-length matches freeze this tool?
No. Patterns that can match an empty string, like a lone \d*, are stepped past automatically, so the match list finishes instead of looping forever.