Free Regex Tester Online with Plain-English Explanation

Test regex patterns with live highlighting, capture groups and replace, and get each part of the pattern explained in plain English.

Regular expression

//g

Test string

Matches (0)

Contact: alice@example.com, bob@test.com

Replace matches

Explanation

(Start of capturing group 1
\wMatches any word character (letter, digit or underscore)
+Repeat the previous item one or more times
)End of group
@Matches the literal text "@"
(Start of capturing group 2
\wMatches any word character (letter, digit or underscore)
+Repeat the previous item one or more times
)End of group
\.Matches a literal "."
comMatches the literal text "com"

How to use it

Enter your pattern and choose flags.
Paste the text to test; matches are highlighted live.
Read the match details and the explanation, or turn on replace to preview a substitution.

Frequently asked questions

Which regex flavor does it use?

JavaScript (ECMAScript) regular expressions, the same engine your browser uses.

How does the explanation work?

The pattern is split into tokens such as groups, classes, quantifiers and anchors, and each is described in plain English.

Can a bad pattern freeze the page?

Matching runs in a background worker with a time limit, so a pattern with catastrophic backtracking is stopped instead of freezing the page.

What do the flags mean?

g finds all matches, i ignores case, m makes ^ and $ match at each line, s lets . match line breaks, u enables Unicode and y matches only at the current position.

Is my text uploaded?

No. Everything runs in your browser.

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