Regexr

Regex Builder & Tester

The ultimate all-in-one tool to create, test, and master regular expressions. From AI-powered generation to manual building and comprehensive testing.

AI Powered
Interactive
Real-time Testing

🤖 AI Regex Generator

💡

How to Use AI Generation

Describe what you want to match in plain English, and I'll suggest regex patterns! I understand many variations and synonyms. No quotes needed - just type naturally!

✓ Try these examples:
• validate emails
• extract phone numbers
• match website links
• find credit cards
• check passwords
• get dates from text
💡 I understand:
• Synonyms (emails = e-mails)
• Plurals (phone = phones)
• Action words (find, extract, match)
• Common variations

Manual Regex Builder

Build your regex pattern step by step using components

Current Pattern
Empty

Current Pattern

Click components below to build your regex pattern...
🔤

Basic Characters

Click any component to add to your pattern

7 items
.

Any character except newline

a.c matches "abc", "axc"

\d

Any digit (0-9)

\d+ matches "123", "7"

\w

Word character (letter, digit, underscore)

\w+ matches "hello", "test_123"

\s

Whitespace character

\s+ matches spaces, tabs

\D

Non-digit character

\D+ matches "abc", "xyz"

\W

Non-word character

\W+ matches "!@#", "..."

\S

Non-whitespace character

\S+ matches "hello", "123"

🔢

Quantifiers

Click any component to add to your pattern

8 items
*

Zero or more

a* matches "", "a", "aaa"

+

One or more

a+ matches "a", "aaa"

?

Zero or one

a? matches "", "a"

{n}

Exactly n times

a{3} matches "aaa"

{n,}

n or more times

a{2,} matches "aa", "aaa"

{n,m}

Between n and m times

a{2,4} matches "aa", "aaa"

*?

Non-greedy zero or more

Lazy matching

+?

Non-greedy one or more

Lazy matching

📝

Character Classes

Click any component to add to your pattern

7 items
[abc]

Any character in brackets

[abc] matches "a", "b", "c"

[^abc]

Any character NOT in brackets

[^abc] matches "d", "e", "f"

[a-z]

Character range

[a-z] matches lowercase letters

[A-Z]

Uppercase letters

[A-Z] matches "A", "B", "C"

[0-9]

Digit range

[0-9] matches any digit

[a-zA-Z]

All letters

Matches any letter

[a-zA-Z0-9]

Alphanumeric

Letters and numbers

⚓

Anchors

Click any component to add to your pattern

6 items
^

Start of string/line

^hello matches "hello world"

$

End of string/line

world$ matches "hello world"

\b

Word boundary

\bcat\b matches "cat" not "category"

\B

Non-word boundary

\Bcat\B matches "category"

\A

Start of string only

Beginning of entire string

\Z

End of string only

End of entire string

🔗

Groups & Alternation

Click any component to add to your pattern

7 items
()

Capturing group

(abc) captures "abc"

(?:)

Non-capturing group

(?:abc) groups without capture

|

Alternation (OR)

cat|dog matches "cat" or "dog"

(?=)

Positive lookahead

a(?=b) matches "a" followed by "b"

(?!)

Negative lookahead

a(?!b) matches "a" not followed by "b"

(?<=)

Positive lookbehind

(?<=a)b matches "b" preceded by "a"

(?<!)

Negative lookbehind

(?<!a)b matches "b" not preceded by "a"

⭐

Special Characters

Click any component to add to your pattern

8 items
\n

Newline character

Line break

\t

Tab character

Tab space

\r

Carriage return

Return character

\.

Literal dot

Escapes the dot metacharacter

\*

Literal asterisk

Escapes the * metacharacter

\+

Literal plus

Escapes the + metacharacter

\?

Literal question mark

Escapes the ? metacharacter

\\

Literal backslash

Escapes the backslash

💡 Quick Tips for Manual Building

🎯 Building Strategy

Start with basic characters, add quantifiers, then use anchors to position your pattern precisely.

🔍 Testing as You Go

Test your pattern after each addition to understand how components interact with each other.

⚡ Common Patterns

Email: ^[\\w.-]+@[\\w.-]+\\.[a-zA-Z]{2,}$ | Phone: ^\\d{3}-\\d{3}-\\d{4}$

🛡️ Escaping Characters

Use backslash (\\) to escape special characters when you want their literal meaning.

📚 Preset Patterns

4 patterns

Email Address

Pattern

Validates email addresses

Regex Pattern:
[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
Example Match:
user@example.com

Phone Number (US)

Pattern

US phone number formats

Regex Pattern:
\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4}
Example Match:
(555) 123-4567

URL/Website

Pattern

HTTP/HTTPS URLs

Regex Pattern:
https?:\/\/(www\.)?[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
Example Match:
https://www.example.com

IPv4 Address

Pattern

IPv4 network addresses

Regex Pattern:
\b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b
Example Match:
192.168.1.1

Regex Tester

Test your regular expressions with live matching and validation

Matches Found
0

Regular Expression Pattern

Test Text

Results

🎯

Enter a regex pattern to see results

💡 Testing Tips

🎯 Pattern Building

Start simple and build complexity gradually. Test each addition to understand its effect.

🔍 Flag Usage

Global flag finds all matches, ignore case for case-insensitive matching, multiline for line-by-line processing.

📝 Test Data

Use varied test data including edge cases, empty strings, and unexpected input formats.

⚡ Performance

Avoid catastrophic backtracking with careful quantifier placement and non-greedy matching.

📝

No Pattern to Export

Create a regex pattern first to generate code snippets