Will a pattern that works here also work on my server?

Usually, but not always. Browser JavaScript regex and server-side engines can differ in supported syntax, so test the pattern in its actual runtime before relying on it.

Can I test sensitive text against a pattern?

Yes. Matching happens entirely in your browser, so the text you paste is never uploaded anywhere.

Regex Tester

Write a regular expression, set its flags, and paste text to check against it. Matches, their ranges, and capture groups highlight as you type, using your browser's own JavaScript regex engine.

Pattern

Flags

Common Patterns

Test String

How to use

Enter a pattern and choose flags such as global or case-insensitive.
Paste the text you want to test the pattern against.
Inspect the highlighted matches and their capture groups.

Frequently asked questions

Will a pattern that works here also work on my server?: Usually, but not always. Browser JavaScript regex and server-side engines can differ in supported syntax, so test the pattern in its actual runtime before relying on it.
Can I test sensitive text against a pattern?: Yes. Matching happens entirely in your browser, so the text you paste is never uploaded anywhere.

Privacy

The pattern and test text are evaluated in your browser and never sent to a server.

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