Regex Tester
Online regex tester with real-time match highlighting
//gm
📖 Regex Tester Guide
Introduction
The Regex Tester is an online regular expression debugger. Enter a pattern and test text, see matches highlighted in real-time. Supports all flags (g/i/m/s/u/y), capture groups, and match positions.
Features
- Real-time highlighting: See matches instantly
- Capture groups: View $1, $2 group contents
- Match positions: See where each match occurs
- Error feedback: Detailed syntax error messages
- Full flags: g, i, m, s, u, y
How to Use
- Enter a regex pattern (without delimiters)
- Select flags
- Enter test text
- Matches highlight automatically
Example
Pattern: \d{3,4}[ -]?\d{7,8} → Phone numbers
Pattern: [\w.-]+@[\w.-]+\.[\w]{2,} → Emails
Pattern: https?://[^\s]+ → URLs
Use Cases
- Form validation (email, phone, ID)
- Log parsing and analysis
- Data cleaning and transformation
- Learning and debugging regex patterns