Regex Tester
Test regex patterns with flags, live matches and highlighted results.
Flags
Active: g
Test text
96 characters
Matches
Run the test to see matches and text highlighting.
100% local processing in your browser
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Benefits
- Validates regex quickly.
- Shows clear errors for invalid patterns.
- Includes visual highlighting for matches.
Controlled testing for regular expressions
A regular expression can behave differently according to its flags and input. Displaying matches, positions and capture groups makes the pattern easier to review before it is used in validation or transformation code.
- When it is useful
- Test extraction and search rules with common JavaScript flags. Highlighted input helps reveal patterns that match too broadly or fail to cover expected cases.
- Privacy and scope
- The pattern and sample text run locally. Replace credentials and personal data with anonymous examples when preparing a test case that may later be shared.
- Result limitations
- Results follow JavaScript regular-expression behavior. Patterns from other platforms may differ in syntax or Unicode support, and complex patterns can be expensive on very large inputs.
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Frequently asked questions
Which flags are supported?
g, i, m, s and u.
Is test text sent to a server?
No. Everything runs in the browser.
Test regular expressions with real-time feedback
Regex Tester speeds up pattern debugging for validation, extraction and text processing workflows.
Use live match highlighting to iterate expressions quickly and reduce implementation errors.