Regex Tester Tool
Test and debug regular expressions with real-time matching
Enter Regex and Test Text
Characters: 0
Lines: 1
Quick Examples:
Quick Cheatsheet:
\d
Any digit (0-9)
\w
Word character
\s
Whitespace
.
Any character
[abc]
Any of a, b, or c
[^abc]
Not a, b, or c
a|b
a or b
a*
0 or more of a
0
Pattern Length
0
Text Length
Testing regex pattern…
Regex Test Results
Regex Matches Found
Total Matches:
0
Capture Groups:
0
Pattern Flags:
None
Execution Time:
0ms
Pattern:
How Regex Testing Works
Regular expressions are patterns used to match character combinations in strings:
- Literal characters match themselves
- Metacharacters have special meaning (., *, +, ?, etc.)
- Character classes match sets of characters ([a-z], \d, \w, etc.)
- Quantifiers specify how many times to match (?, *, +, {n,m})
- Anchors match positions (^ for start, $ for end)
// Example: Match email addresses
Pattern: /\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b/gi
Text: “Contact us at info@example.com or support@test.org”
Matches: “info@example.com”, “support@test.org”
Enter a regex pattern and test text to see matches here
Regex Test History
Your regex test history will appear here
About Regular Expressions
Regular expressions are patterns used for text search and manipulation.
- Common Uses: Validation, search/replace, parsing, data extraction
- JavaScript Support: Full regex support via RegExp object
- Flags: i (case-insensitive), g (global), m (multiline), s (dotall), u (unicode), y (sticky)
- Performance: Complex regex can be slow – test with realistic data
Security Note: Be cautious with user-provided regex patterns as they can cause ReDoS (Regex Denial of Service) attacks.