Validate
Regex Tester
Wrap long lines in the input and output
Pattern and text
Put /pattern/flags or a bare pattern on the first line, then the text to test.
Matches
Validate
Put /pattern/flags or a bare pattern on the first line, then the text to test.
The first line is the regular expression. Write it as /pattern/flags or as a bare pattern with no slashes. Everything after the first line break is the text the pattern is tested against, and that text may be empty.
Ignore case, multiline, dot-all and Unicode are added to any flags already on that line. The global flag is always on, so every match is listed, and the sticky flag is left off. Each match is reported as Match N at I-J: text, then Group K: text for every capturing group. An unmatched group is Group K: (none). When nothing matches, the report is No match. A zero-length match advances one code unit so a pattern such as a* cannot loop, and the report stops after 200 matches.
This uses the JavaScript RegExp dialect, not PCRE or Java. Matching runs in your browser and the text you paste is never uploaded.
It runs a JavaScript regular expression against the text below the first line and lists every match with its capturing groups. Offsets are UTF-16 indexes into that text, the same indexes RegExp reports.
Put the pattern on the first line, either as /pattern/flags or as the pattern alone. The last unescaped / on a slash-delimited line starts the flags. The rest of the input, after the first line break, is the subject.
JavaScript RegExp, not PCRE or Java. Lookaround, named groups and escapes follow the engine in your browser. A pattern or flag that engine rejects is an invalid regular expression.
Ignore case adds i, multiline adds m, dot matches newline adds s, and Unicode adds u. Those options join any flags on the pattern line. g is always on so every match is listed. The sticky flag y is not used.
The report keeps at most 200 matches and then adds the line Stopped after 200 matches. A pattern that can match at every position, including an empty pattern, would otherwise list one hit per character.
No. Matching runs in your browser and the text you paste is never uploaded, logged or stored. Google Analytics records page views and feature use, never content.
Check that text is valid JSON and report the first syntax error.
Check that XML is well-formed and point at the first error.
Explain a cron expression and list the next run times in UTC.
Turn text into a valid JSON string literal, or decode one back to plain text.
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