Is Regex Tester free?

Yes. Test regular expressions free on TheToolss.

Which flavor of regex is used?

It follows JavaScript RegExp behavior in your browser.

Can I test with flags like global or case-insensitive?

Yes. Enable common flags while you experiment.

Is my sample text uploaded?

No. Matching runs locally in the browser.

Does it replace text too?

Focus is on testing matches; use your editor for bulk replace once the pattern is solid.

Regex Tester

Test regular expressions against sample text.

100% free
Private in browser
No signup
No watermarks

Pattern

Flags

Test string

1 match(es)

Live results

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About Regex Tester

Iterate on regular expressions without bouncing between docs and a REPL. Regex Tester on TheToolss lets you write a pattern, set common flags, and inspect matches against sample text in real time. Use it to debug email validators, parsers, or search filters before shipping code. Patterns and samples stay in your browser — free, private, and no signup.

How to use Regex Tester

Enter a regular expression pattern.
Add sample text and choose flags if needed.
Review matches and adjust the pattern.

Key features

Live regex matching against sample text
Common flag support for testing
Faster pattern debugging before coding
Works on desktop and mobile browsers
Private — patterns are not uploaded

Frequently asked questions

Is Regex Tester free?: Yes. Test regular expressions free on TheToolss.
Which flavor of regex is used?: It follows JavaScript RegExp behavior in your browser.
Can I test with flags like global or case-insensitive?: Yes. Enable common flags while you experiment.
Is my sample text uploaded?: No. Matching runs locally in the browser.
Does it replace text too?: Focus is on testing matches; use your editor for bulk replace once the pattern is solid.

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