Regex Pattern Tester — Test and Share Regular ExpressionsRegex Tester
Build, test, and share regular expressions with a clean, developer-friendly interface. Write your pattern, paste test strings, and see line-by-line match results instantly. Save your regex as a shareable page so teammates can reference the same pattern, test cases, and explanation. Perfect for code reviews, documentation, onboarding guides, and quick regex validation. No signup required.
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Email Address Validator
Validates that a string follows a standard email format: local part, @ symbol, domain, and TLD.
3/7
matches
Pattern
/^[\w.-]+@[\w.-]+\.\w{2,}$/i
Test String
1✓user@example.com
2✓john.doe@company.co.uk
3✗invalid-email
4✗@missing-local.com
5✗name@.com
6✓test@domain.io
7✗hello@world
Explanation
^ — Start of string
[\w.-]+ — One or more word chars, dots, or hyphens (local part)
@ — Literal @ symbol
[\w.-]+ — Domain name
\. — Literal dot before TLD
\w{2,} — TLD with 2+ characters
$ — End of string
Notes
This is a basic email regex. For production use, consider RFC 5322 compliance or use a dedicated email validation library.
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Everything You Need
Regex Tester comes packed with powerful features.
Pattern Display
View your regex in a code-style format with forward slashes and flags, exactly as it appears in code.
Line-by-Line Matching
Each line of your test string is checked against the pattern, showing a clear match or no-match indicator.
Shareable Patterns
Save your regex, test strings, and explanation as a permanent page. Share the link with your team.
Developer-Friendly UI
Monospace fonts, dark code blocks, and a clean layout designed for developers who live in the terminal.
Choose Your Template
Email Address Validator
Validates that a string follows a standard email format: local part, @ symbol, domain, and TLD.
3/7
matches
Pattern
/^[\w.-]+@[\w.-]+\.\w{2,}$/i
Test String
1✓user@example.com
2✓john.doe@company.co.uk
3✗invalid-email
4✗@missing-local.com
5✗name@.com
6✓test@domain.io
7✗hello@world
Explanation
^ — Start of string
[\w.-]+ — One or more word chars, dots, or hyphens (local part)
@ — Literal @ symbol
[\w.-]+ — Domain name
\. — Literal dot before TLD
\w{2,} — TLD with 2+ characters
$ — End of string
Notes
This is a basic email regex. For production use, consider RFC 5322 compliance or use a dedicated email validation library.
Email ValidatorUse Template
Phone Number Matcher
Matches international and domestic phone number formats with optional country code, parentheses, and separators.
4/7
matches
Pattern
/^\+?[1-9]\d{0,2}[-.\s]?\(?\d{1,4}\)?[-.\s]?\d{1,4}[-.\s]?\d{1,9}$/
Test String
1✓+1 (555) 123-4567
2✓555-123-4567
3✓+44 20 7946 0958
4✗123
5✓+1-800-555-0199
6✗(555) 123-4567
7✗abc-def-ghij
Explanation
\+? — Optional plus sign for country code
[1-9]\d{0,2} — Country code (1-3 digits, no leading zero)
[-.\s]? — Optional separator
\(?\d{1,4}\)? — Optional parenthesized area code
Remaining groups match the local number with optional separators.
Notes
Phone validation is notoriously difficult. For production, use a library like libphonenumber.
Phone NumberUse Template
URL Matcher
Matches HTTP and HTTPS URLs with domain, optional path, and query parameters.
4/7
matches
Pattern
/https?:\/\/[\w.-]+(?:\.[a-z]{2,})(?:\/[^\s]*)?/gi
Test String
1✓https://example.com
2✓http://subdomain.example.co.uk/path?q=1
3✗not-a-url
4✗ftp://wrong-protocol.com
5✓https://simplyonline.ai/colortools
6✗http://localhost
7✓https://api.service.com/v2/users?page=3&limit=10
Explanation
https? — Match http or https
:\/\/ — Literal ://
[\w.-]+ — Domain name with subdomains
(?:\.[a-z]{2,}) — TLD (2+ chars)
(?:\/[^\s]*)? — Optional path and query string
Notes
This catches most common URLs but may miss edge cases like IP addresses or ports. For complete URL parsing, use the URL constructor.
URL MatcherUse Template
Date Format Matcher (YYYY-MM-DD)
Matches dates in ISO 8601 format (YYYY-MM-DD) with basic month and day validation.
3/7
matches
Pattern
/^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$/
Test String
1✓2026-02-28
2✗2026-13-01
3✗2026-00-15
4✓2025-12-31
5✓2026-02-30
6✗26-01-01
7✗2026-1-5
Explanation
\d{4} — Four-digit year
(0[1-9]|1[0-2]) — Month 01-12
(0[1-9]|[12]\d|3[01]) — Day 01-31
Note: This does not validate days per month (e.g., Feb 30 passes).
Notes
For strict date validation, parse with new Date() after matching the format. This regex only validates the shape.
Date FormatUse Template
Strong Password Validator
Validates that a password contains at least one lowercase letter, one uppercase letter, one digit, one special character, and is at least 8 characters long.
2/7
matches
Pattern
/^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*]).{8,}$/
Test String
1✓Str0ng!Pass
2✗weakpassword
3✗12345678
4✗NoSpecial1
5✗Sh0rt!
6✓C0mpl3x#Password
7✗aB1!
Explanation
(?=.*[a-z]) — At least one lowercase
(?=.*[A-Z]) — At least one uppercase
(?=.*\d) — At least one digit
(?=.*[!@#$%^&*]) — At least one special char
.{8,} — Minimum 8 characters total
Notes
Password strength rules vary by application. NIST guidelines now recommend length over complexity. Consider a passphrase approach.
Password RulesUse Template
HTML Tag Matcher
Matches opening and self-closing HTML tags with optional attributes. Does not match closing tags.
5/8
matches
Pattern
/<([a-z][a-z0-9]*)\b[^>]*\/?>/gi
Test String
1✓<div class="container">
2✓<img src="photo.jpg" />
3✓<p>
4✗Not a tag
5✓<br/>
6✓<h1 id="title">
7✗< invalid>
8✗<123bad>
Explanation
< — Opening angle bracket
([a-z][a-z0-9]*) — Tag name starting with a letter
\b — Word boundary
[^>]* — Any attributes (anything except >)
\/? — Optional self-closing slash
> — Closing angle bracket
Notes
Regex is not suitable for full HTML parsing. Use a proper DOM parser for production. This is useful for quick searches and simple extraction.
HTML TagUse Template
IPv4 Address Validator
Validates IPv4 addresses with proper octet range checking (0-255 per octet).
5/8
matches
Pattern
/^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$/
Test String
1✓192.168.1.1
2✓10.0.0.255
3✗256.1.1.1
4✓0.0.0.0
5✓255.255.255.255
6✗192.168.1
7✗1.2.3.4.5
8✓172.16.254.1
Explanation
(25[0-5]|2[0-4]\d|[01]?\d\d?) — Matches 0-255
\. — Literal dot separator
{3} — First three octets followed by dot
Final group matches the fourth octet without trailing dot.
Notes
This validates IPv4 only. For IPv6, you need a separate (much longer) pattern or use built-in parsing.
IP AddressUse Template
Custom Pattern
A simple word boundary matcher. Replace this with your own pattern.
3/3
matches
Pattern
/\b\w+\b/g
Test String
1✓Hello World
2✓Test your regex here
3✓123 numbers too
Explanation
\b — Word boundary
\w+ — One or more word characters
\b — Word boundary
This matches individual words in any text.
Notes
Replace this with your own pattern and test strings.
Custom PatternUse Template
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Frequently Asked Questions
Each line of your test string is tested against your regex pattern. Lines that match show a green check mark, lines that do not match show a red X.
Yes. Save your pattern and you get a permanent link. Anyone can view the pattern, flags, test strings, and your explanation.
All standard JavaScript regex flags: g (global), i (case insensitive), m (multiline), s (dotAll), u (unicode), and y (sticky).
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