Regex Tester
Test and debug regular expressions
Pattern Status
Not tested
Matches Found
0
Flags
g
Regular Expression
Enter your regex pattern
//g
Replace
Replace matched text
Test String
Text to test against the pattern
Regex Reference
Character Classes
. - Any character
\d - Digit [0-9]
\w - Word [A-Za-z0-9_]
\s - Whitespace
\D - Not digit
\W - Not word
\S - Not whitespace
Quantifiers
* - 0 or more
+ - 1 or more
? - 0 or 1
{n} - Exactly n
{n,} - n or more
{n,m} - Between n and m
Test and debug regular expressions with real-time match highlighting. Write a regex pattern, provide test text, and see all matches highlighted instantly. View captured groups, test different flags (global, case-insensitive, multiline), and iterate quickly on complex patterns.
Key Features
- ✓Real-time match highlighting
- ✓Capture group display
- ✓Flag toggles (g, i, m, s)
- ✓Match count and positions
- ✓JavaScript regex syntax
- ✓Test against multiple lines
How to Regex Tester Online
- 1
Enter regex pattern
Type your regular expression.
- 2
Enter test text
Paste the text to test against.
- 3
View matches
Matches are highlighted in real time with group details.
Common Use Cases
- •Developing and debugging regex for form validation
- •Testing patterns for log file parsing
- •Building regex for find-and-replace operations
- •Learning regex with instant visual feedback
- •Validating email, URL, or phone number patterns
Frequently Asked Questions
What regex flavor is supported?▼
JavaScript regular expressions, which support lookaheads, lookbehinds (ES2018+), named groups, and Unicode escapes.
Can I test replacement strings?▼
This tool focuses on matching. For regex replacement, use the "Find & Replace Regex" text tool.