Regex Tester
Test, debug and understand regular expressions instantly with live match highlighting, capture groups and helpful pattern explanations.
Flags
Test Mode
Each line in the test cases will be treated as an individual test case.
Status
Test Case Results
Enter a valid regex pattern and add test cases above to see results here.
Pattern Explanation
Enter a regular expression to see its pattern explanation.
Privacy
Everything is processed locally in your browser. Your pattern and test data are never uploaded or stored.
How To Use
Enter your pattern
into the Regex Pattern field.
Choose flags
to control how the pattern is applied — g, i, m, s, u or y.
Pick a test mode
Each Line to test line by line, or Entire Text to test everything at once.
Add your test cases
by pasting or typing them into the Test Cases editor.
Review the results
highlighted directly in each test case, with match details and a pattern explanation below.
About Regex Tester
The DevToolVerse Regex Tester helps you build, test, check and validate regular expressions directly in your browser. Whether you're validating form input, extracting data, or learning how a pattern works, this tool makes it easy to see matches, capture groups and explanations in one place.
All processing happens locally in your browser, meaning your patterns and test data are never uploaded to a server. This keeps your input private while making it fast to experiment with regular expressions.
Features
Live Match Highlighting
see matches highlighted directly in your test cases as you type.
Capture Group Breakdown
inspect every capture group from each match individually.
JavaScript Regex Flags
toggle g, i, m, s, u and y to control how your pattern behaves.
Two Test Modes
test each line individually or the entire text as a single string.
Pattern Explanations
understand what each part of your regular expression does.
Runs entirely in your browser
your pattern and test data never leave your device.
Quick Reference
A compact reference of the most commonly used regular expression symbols.
| Symbol | Meaning |
|---|---|
| . | Any character |
| \d | Digit |
| \w | Word character |
| \s | Whitespace |
| + | One or more |
| * | Zero or more |
| ? | Optional |
| ^ | Start of string |
| $ | End of string |
| (...) | Capture group |
| [...] | Character class |
Common Patterns
^[\w.+-]+@[\w-]+\.[a-zA-Z]{2,}$
URL
^https?:\/\/[\w.-]+\.[a-zA-Z]{2,}(\/\S*)?$
IPv4
^(\d{1,3}\.){3}\d{1,3}$
Numbers
^-?\d+(\.\d+)?$
Whitespace
\s+
Date
^\d{4}-\d{2}-\d{2}$
Phone Number
^\+?[\d\s-]{7,15}$
Limitations & Important Notes
- The Common Patterns are simple examples that demonstrate common pattern structures, not production-grade validators — test and adapt them against your own real-world cases before relying on them.
- The bundled IPv4 example checks the general digit/group structure but does not enforce the valid 0–255 range per segment.
- The bundled Date example checks the YYYY-MM-DD shape but does not validate whether the date is a real calendar date.
- The bundled Phone Number example is a simplified pattern and can accept strings made only of allowed characters without requiring an actual digit.
- The bundled Email example is a simplified pattern and is not intended to provide complete email-address validation.
- In Each Line mode, blank lines are ignored and do not produce individual test-case result rows.
- Lines are tested exactly as entered — surrounding whitespace is not automatically trimmed before matching.
FAQ
A regex tester lets you write a regular expression and check it against sample text to see what it matches, without writing any code. It also validates the pattern itself — an invalid regular expression is flagged immediately, so you can confirm a pattern is both syntactically valid and matching the way you expect before using it in your own code.
This tool uses JavaScript's native regular expression engine, so patterns behave exactly as they would in a browser or Node.js.
g (global) finds every match instead of stopping at the first. i makes matching case-insensitive. m (multiline) makes ^ and $ match the start/end of each line instead of the whole string. s (dot all) makes . also match newline characters. u enables full Unicode matching. y (sticky) matches only starting from the current position rather than scanning ahead. The Flags panel above shows the same descriptions next to each flag.
Each Line tests every line in your test cases individually, while Entire Text treats the whole input as a single string. In Each Line mode, blank lines are ignored and do not produce their own test-case result.
No. Everything runs locally in your browser. Your pattern and test data are never uploaded to any server.