Pattern Testing
Validate expressions with common JavaScript regex flags.
Regex Tester
Test regular expressions against text with flags, highlighted matches, and replacement preview.
Match HighlightingReplace PreviewLocal Testing
Regex tester
Test a pattern, see matches and replacements live.
Pattern
//gm
0 chars · 0 bytes
Matches
0 matches found
Match list
No matches yet.
Replace result
Capabilities
What this tool handles
Use Regex Tester to check the input, tune the settings, and copy a clean output.
Match Highlighting
See matches in context with indexes and match counts.
Copy Matches
Copy matched values or preview replacement output.
Workflow
Run it in three steps
Test JavaScript regular expressions against sample text.
1
Enter Pattern
Type a regular expression and choose flags such as g, i, or m.
2
Add Test Text
Paste the text you want to match against.
3
Review Matches
Check highlighted matches, indexes, and replacement output.
Good for
Common jobs this tool supports
Pattern FlagsToggle common regex flags
HighlightsMatches are shown in context
Replace PreviewPreview replacement results locally
Copy MatchesCopy matched values quickly
FAQ
Answers before you run it
Practical notes about output, privacy, and common settings.
It tests JavaScript regular expressions using the browser RegExp engine.
Use next