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Regex Tester – Live Regular Expression Tester Free

4.8
(393 votes)

Rigorously test intricate Regular Expressions displaying live visual highlights, precise capture groups, and match insights spanning major JS parameters.

//gi
/[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}/gi
Test String
2 matches
Contact us at support@example.com or sales@company.co.in for help.

Match Details

#1
support@example.com
Index: 14Length: 19
#2
sales@company.co.in
Index: 37Length: 19

How to Use the Regex Tester

1

Enter a Pattern

Type your regular expression in the pattern field (without slashes). Use one of the examples to get started quickly.

2

Toggle Flags

Enable flags like g (global), i (case-insensitive), or m (multiline) with the flag buttons.

3

See Live Matches

Matches are highlighted in real-time. Expand each match card to see capture groups and index positions.

Frequently Asked Questions

What is regex (regular expression)?

A regex is a pattern used to match, search, or replace strings. It's a powerful tool for text processing used by developers daily.

What does the 'g' flag do?

The global flag (g) makes the regex engine find all matches instead of stopping at the first one.

How do I match capture groups?

Use parentheses ( ) to create capture groups. Group matches are shown as $1, $2 etc. in each match card.

Is there a character limit for test text?

No hard limit. However, extremely complex patterns on very large texts may be slow (regex processing is done in-browser).

Is my data safe?

Yes, 100% client-side. Your patterns and test strings never leave your device.

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