Regex Tester & Matcher
Write and test regular expressions against reference text with instant match highlights and flag settings.
Interactive Tool Workspace
100% Client-Side ProcessingRegex Details
/
/g
Flags
Highlight Match Output
0 Match(es) found
How to use Regex Tester & Matcher
- Input pattern: Write your regular expression pattern string in the regex box.
- Set search flags: Toggle flags (g for global search, i for case-insensitive, m for multiline match).
- Add test text: Type or paste sample blocks in the test area.
- Inspect matches: Match highlights automatically refresh in the output container.
Frequently Asked Questions
Q: What does the 'g' flag do?
The 'g' (global) flag checks all occurrences of matches across the text. If disabled, standard Javascript regex engines stop compiling after the first matched segment.
Q: Why do some matches cause errors?
If your expression has unmatched parentheses, brackets, or invalid escaping sequences, the browser compiler throws a syntax exception, which we flag in the warning block.