Which regular-expression syntax does this tester use?

It uses the JavaScript RegExp engine and supports the g, i, m, s, u, and y flags exposed in the interface.

What does the global flag change?

Without g, JavaScript returns the first match. With g enabled, the page finds and highlights every non-overlapping match.

The summary reports the groups captured by the first match while the highlighter still marks all matches selected by the flags.

LocalFree

Test JavaScript regular expressions against sample text. See live match highlights, capture groups, and supported flags.

Regular expression

Flags: g global, i ignore case, m multiline, s dot all, u unicode, y sticky.

Test text

Highlighted matches

Test your regex against this sample text!

7 matches

Runs in your browser; files and input stay on this device

1Enter a JavaScript regular expression without surrounding slashes.
2Choose the flags you need and paste the text to test.
3Review highlighted matches, the match count, and capture groups; correct the pattern if an error appears.

Which regular-expression syntax does this tester use?: It uses the JavaScript RegExp engine and supports the g, i, m, s, u, and y flags exposed in the interface.
What does the global flag change?: Without g, JavaScript returns the first match. With g enabled, the page finds and highlights every non-overlapping match.
Why are capture groups shown only for the first match?: The summary reports the groups captured by the first match while the highlighter still marks all matches selected by the flags.