Regex Tester — Regular Expression Debugger
Test and debug regular expressions with live match highlighting.
//
Matches (1)
Index: 0
Match: ""
How It Works
01
Write Pattern
Enter your regex pattern and flags
02
Test String
Paste text to test against the pattern
03
See Matches
View highlighted matches and capture groups
Help Us Improve
Your feedback helps us build better tools.
About Regex Tester
Our free Regex Tester lets you write, test, and debug regular expressions with live match highlighting. Supports global, case-insensitive, multiline, and dotall flags.
See matches with index positions and capture groups. Load common patterns for email, URL, phone numbers, dates, and hex colors with one click.
Essential for developers, QA engineers, and students learning pattern matching for validation, parsing, and text processing.
Read the full guide: How to test regular expressions online
When Should You Use Regex Tester?
Form validation
Test email, phone, and URL patterns before deploying.
Log parsing
Debug regex patterns against sample log lines.
Data extraction
Find and verify capture groups in structured text.
Learning regex
Experiment with patterns and see matches instantly.
Code review
Validate regex used in production code against edge cases.