Tools / Regex Tester

Regex Tester

Test regular expressions with real-time matching. See matches highlighted, capture groups extracted, and common patterns ready to use.

7,800 AI Tokens Used
Feb 1, 2026 Created
developertext
Categories
//g
Enter a pattern to start matching

Regular expressions are tested locally in your browser. No data is sent to any server.

How This Tool Was Built

This tool was created entirely by AI. Here's the exact prompt used to generate it:

Prompt Used 
Create a Regex Tester tool with these features:

1. Pattern input with regex delimiters display (/pattern/flags)
2. Flag toggles: g (global), i (case insensitive), m (multiline), s (dotAll)
3. Test string textarea
4. Real-time matching as user types
5. Highlighted matches in the test string
6. Match results list showing:
   - Match number and index position
   - Matched text
   - Capture groups if any
7. Common patterns quick buttons (email, URL, phone, date, IP)
8. Copy regex button
9. Error display for invalid regex
10. Use new RegExp() constructor safely (no eval)

Make it developer-friendly with orange as the accent color.
AI
Claude AI Model
#
7,800 Tokens Used
100%
AI-Generated Code Origin