live regex tester and debugger. write a pattern, paste test text, and see matches highlighted in real time.
matches will be highlighted here
Regex Tester is a live regular expression debugger. Write a regex pattern, paste test text, and see matches highlighted in real time. Capture groups are color-coded so you can see exactly what each group captures.
The tool supports all standard JavaScript regex flags including global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u). See match count, group captures, and match indices as you type.
Perfect for building and debugging regex patterns for form validation, data parsing, log analysis, and text processing. Everything runs in your browser with no data sent to any server.
Enter your regex pattern
Type a regular expression in the pattern field. Add flags like g, i, m, s, u as needed.
Paste test text
Paste the text you want to match against in the test area.
See matches highlighted
Matches are highlighted in the text in real time as you edit either the pattern or the test text.
Inspect capture groups
Each capture group is shown with its matched content, index, and color-coded highlighting.
Form validation
Build and test regex patterns for validating emails, phone numbers, URLs, and other input formats.
Log parsing
Develop regex patterns to extract timestamps, error codes, and IP addresses from log files.
Data extraction
Create patterns to pull specific fields from unstructured text data.
Search and replace
Test complex find-and-replace patterns before applying them to your codebase.
Learning regex
Experiment with patterns and see instant visual feedback to understand how regex works.
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