Developer utility
Standalone tool pageRegex Tester - Online Regular Expression Testing
Test regular expressions against text with live matching, group extraction, and syntax highlighting.
Regex Tester
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| Match # | Group # | Value |
|---|---|---|
| No matches | ||
How It Works
Enter your values into Regex Tester, let the browser process the data, and review the result instantly.
Example
Example: use Regex Tester to test a scenario before making a decision.
When to use this tool
- Debugging complex regular expressions.
- Extracting data groups from log files or raw text.
- Validating input formats (like emails, phone numbers, or passwords).
How to use the Regex Tester
- Enter your regular expression pattern in the top input.
- Add flags like "g" (global), "i" (case-insensitive), or "m" (multi-line) in the flags box.
- Paste your test string in the text area below.
- Matches will be highlighted immediately, and capture groups will be extracted into a table.
Frequently Asked Questions
What is a Regular Expression (Regex)?
A regular expression is a sequence of characters that specifies a search pattern in text. It is widely used by developers for text search, validation, and string manipulation.
Is my text sent to a server?
No. All regex matching and string processing happens locally in your web browser. No data is sent over the internet.