Regex Tester

How to Use the Regex Tester

1. Enter Pattern: Type your regular expression with or without delimiters (e.g., /pattern/flags or pattern)
2. Add Test Text: Input the text you want to test your regex pattern against
3. Include Flags: Use flags like 'g' (global), 'i' (case-insensitive), 'm' (multiline)
4. Test Pattern: Click "Test Regex" to see matches highlighted in the results
5. Refine Pattern: Adjust your regex based on the highlighted matches
6. Validate Results: Ensure your pattern matches exactly what you intended

Regex Tips & Common Patterns

• Email Validation: /^[^\s@]+@[^\s@]+\.[^\s@]+$/i for basic email format
• Phone Numbers: /^\d{3}-\d{3}-\d{4}$/ for XXX-XXX-XXXX format
• URLs: /https?:\/\/[^\s]+/g to match web addresses
• Digits Only: /^\d+$/ to match numbers only
• Word Boundaries: /\bword\b/g to match whole words
• Case Insensitive: Use 'i' flag for case-insensitive matching
• Global Matching: Use 'g' flag to find all matches, not just the first

Regex Syntax & Applications

Common Metacharacters: . (any character), * (zero or more), + (one or more), ? (optional), ^ (start), $ (end)

Character Classes: [abc] (any of a,b,c), [a-z] (any lowercase), \d (digits), \w (word chars), \s (whitespace)

Use Cases: Data validation, text processing, search and replace, log analysis, and input sanitization.

Testing Strategy: Start simple, test edge cases, use online tools for complex patterns, and document your regex.