iKnowABit

Online Regex Tester

Test, debug, and learn Regular Expressions online with real-time highlighting and capture group extraction. 100% private and runs securely in your browser.

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Total Visits
Regex Tester

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/

Match Result
2 match(es)

Contact us at [email protected] or [email protected] for more details.

Match Details
Match 1

[email protected]

Pos: 14-35
Match 2

[email protected]

Pos: 39-55
Regex Cheatsheet
[abc]

A single character of: a, b, or c

[^abc]

Any single character except: a, b, or c

[a-z]

Any single character in the range a-z

[a-zA-Z]

Any single character in the range a-z or A-Z

^

Start of line

$

End of line

\A

Start of string

\z

End of string

.

Any single character

\s

Any whitespace character

\S

Any non-whitespace character

\d

Any digit

\D

Any non-digit

\w

Any word character (letter, number, underscore)

\W

Any non-word character

\b

Any word boundary

(...)

Capture everything enclosed

(a|b)

a or b

a?

Zero or one of a

a*

Zero or more of a

a+

One or more of a

a{3}

Exactly 3 of a

a{3,}

3 or more of a

a{3,6}

Between 3 and 6 of a

About Online Regex Tester

This Online Regular Expression (Regex) Tester helps you write, test, and debug regular expressions in real-time. Whether you are validating emails, extracting data, or cleaning up strings, a reliable regex tester is a must-have for every developer.

🚀 Core Features

  • Real-Time Highlighting See your matches highlighted in real-time as you type your test string or regular expression. No need to click "test" or wait for results.
  • Support for Regex Flags Easily add standard JavaScript regex flags like g (global), i (case-insensitive), and m (multiline) to test exactly how your expression behaves.
  • Match and Group Extraction If your regex uses capturing groups ( ) , the tester will automatically break down and display the captured groups for each match individually. It significantly helps in parsing operations.
  • Built-in Quick Cheatsheet A handy reference table is provided right next to the editor so you don't need to switch tabs to remember how to match digits or whitespace.

🔒 100% Local Privacy Guarantee

Your regular expressions and the text you are testing them against never leave your browser. It is absolutely safe to test sensitive logs, emails, or personal identification strings. The evaluation runs entirely in your local memory.

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