Regex Pattern Library

Search common regex patterns for email, URLs, UUIDs, slugs, and dates, then copy them instantly.

Browse reusable regex patterns

Search patterns

62 patterns found

Email

Validation

Example: hello@utiloom.com

^[^\s@]+@[^\s@]+\.[^\s@]+$

Email (strict RFC 5322)

Validation

Example: user.name+tag@sub.example.com

Test

^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$

URL (http/https)

Validation

Example: https://utiloom.com/tools

Test

https?:\/\/[\w.-]+(?:\.[\w.-]+)+(?:[/?#][^\s]*)?

URL with optional protocol

Validation

Example: www.example.com/path

Test

(?:https?:\/\/)?(?:www\.)?[\w.-]+\.[a-zA-Z]{2,}(?:[/?#][^\s]*)?

HEX color

Format

Example: #0f172a

Test

^#?(?:[0-9a-fA-F]{3}){1,2}$

HEX color (with alpha)

Format

Example: #0f172aff

Test

^#?(?:[0-9a-fA-F]{3,4}){1,2}$

RGB/RGBA

Format

Example: rgba(15, 23, 42, 0.95)

Test

rgba?\(\s*\d{1,3}\s*,\s*\d{1,3}\s*,\s*\d{1,3}(?:\s*,\s*(?:0|1|0?\.\d+))?\s*\)

HSL/HSLA

Format

Example: hsl(210, 40%, 98%)

Test

hsla?\(\s*\d{1,3}\s*,\s*\d{1,3}%\s*,\s*\d{1,3}%(?:\s*,\s*(?:0|1|0?\.\d+))?\s*\)

UUID (v1-v8)

Validation

Example: 550e8400-e29b-41d4-a716-446655440000

Test

^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$

ULID

Validation

Example: 01ARZ3NDEKTSV4RRFFQ69G5FAV

Test

^[0-7][0-9A-HJKMNP-TV-Z]{25}$

Kebab case slug

Format

Example: meeting-overlap-finder

Test

^[a-z0-9]+(?:-[a-z0-9]+)*$

snake_case

Format

Example: user_created_at

Test

^[a-z][a-z0-9]*(?:_[a-z0-9]+)*$

camelCase

Format

Example: getUserName

Test

^[a-z][a-zA-Z0-9]*$

PascalCase

Format

Example: UserProfile

Test

^[A-Z][a-zA-Z0-9]*$

ISO date (YYYY-MM-DD)

Date & Time

Example: 2026-03-09

Test

^\d{4}-\d{2}-\d{2}$

ISO 8601 datetime

Date & Time

Example: 2026-03-09T14:30:00Z

Test

^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}:?\d{2})?$

Time (HH:MM:SS)

Date & Time

Example: 14:30:00

Test

^(?:[01]\d|2[0-3]):[0-5]\d(?::[0-5]\d)?$

12-hour time

Date & Time

Example: 2:30 PM

Test

^(?:0?[1-9]|1[0-2]):[0-5]\d\s*(?:AM|PM|am|pm)$

Date (MM/DD/YYYY)

Date & Time

Example: 03/09/2026

Test

^(?:0[1-9]|1[0-2])\/(?:0[1-9]|[12]\d|3[01])\/\d{4}$

Date (DD/MM/YYYY)

Date & Time

Example: 09/03/2026

Test

^(?:0[1-9]|[12]\d|3[01])\/(?:0[1-9]|1[0-2])\/\d{4}$

Unix timestamp

Date & Time

Example: 1773014400

Test

^\d{10}(?:\d{3})?$

IPv4 address

Network

Example: 192.168.1.1

Test

^(?:(?:25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(?:25[0-5]|2[0-4]\d|[01]?\d\d?)$

IPv6 address

Network

Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

Test

^(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$

MAC address

Network

Example: 01:23:45:67:89:AB

Test

^(?:[0-9a-fA-F]{2}[:-]){5}[0-9a-fA-F]{2}$

Port number

Network

Example: 8080

Test

^(?:[1-9]\d{0,3}|[1-5]\d{4}|6[0-4]\d{3}|65[0-4]\d{2}|655[0-2]\d|6553[0-5])$

Domain name

Network

Example: sub.example.com

Test

^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$

Phone (international)

Validation

Example: +14155552671

Test

^\+?[1-9]\d{1,14}$

Phone (US format)

Validation

Example: (415) 555-2671

Test

^\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4}$

Credit card (Visa)

Security

Example: 4111111111111111

Test

^4[0-9]{12}(?:[0-9]{3})?$

Credit card (Mastercard)

Security

Example: 5500000000000004

Test

^5[1-5][0-9]{14}$

Credit card (any major)

Security

Example: 4111111111111111

Test

^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|6(?:011|5[0-9]{2})[0-9]{12})$

SSN (US)

Security

Example: 123-45-6789

Test

^(?!000|666|9\d{2})\d{3}-(?!00)\d{2}-(?!0000)\d{4}$

ZIP code (US)

Validation

Example: 94102-1234

Test

^\d{5}(?:-\d{4})?$

Postal code (Canada)

Validation

Example: K1A 0B1

Test

^[A-Za-z]\d[A-Za-z]\s?\d[A-Za-z]\d$

Postal code (UK)

Validation

Example: SW1A 1AA

Test

^[A-Z]{1,2}\d[A-Z\d]?\s?\d[A-Z]{2}$

JWT token

Security

Example: eyJhbGci.eyJzdWIi.SflKxwRJ

Test

^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$

Base64 string

Format

Example: SGVsbG8gV29ybGQ=

Test

^[A-Za-z0-9+/]+={0,2}$

MD5 hash

Security

Example: d41d8cd98f00b204e9800998ecf8427e

Test

^[a-fA-F0-9]{32}$

SHA-256 hash

Security

Example: e3b0c44298fc1c149afbf4c8996fb924...

Test

^[a-fA-F0-9]{64}$

HTML tag

Parsing

Example: <div class="box">

Test

<\/?[a-zA-Z][a-zA-Z0-9]*(?:\s[^>]*)?\/?>

HTML comment

Parsing

Example:

Test

<!--[\s\S]*?-->

CSS class selector

Parsing

Example: .container-shell

Test

\.[a-zA-Z_][a-zA-Z0-9_-]*

Markdown link

Parsing

Example: [Utiloom](https://utiloom.com)

Test

\[([^\]]+)\]\(([^)]+)\)

Markdown heading

Parsing

Example: ## Section Title

Test

^#{1,6}\s+.+$

Markdown image

Parsing

Example: ![alt](image.png)

Test

!\[([^\]]*)\]\(([^)]+)\)

JSON key-value

Parsing

Example: "name": "value"

Test

"([^"]+)"\s*:\s*(?:"[^"]*"|\d+|true|false|null)

Semantic version

Format

Example: 2.1.50-beta.1

Test

^\d+\.\d+\.\d+(?:-[a-zA-Z0-9.]+)?(?:\+[a-zA-Z0-9.]+)?$

Cron expression (5-field)

Format

Example: */5 * * * *

Test

^(?:[\d*,/-]+\s){4}[\d*,/-]+$

File path (Unix)

Format

Example: /usr/local/bin/node

Test

^(?:\/[\w.-]+)+\/?$

File extension

Parsing

Example: document.pdf

Test

\.[a-zA-Z0-9]{1,10}$

Image file extension

Parsing

Example: photo.jpg

Test

\.(?:jpe?g|png|gif|webp|svg|avif|bmp|ico)$

Password (strong)

Security

Example: P@ssw0rd!

Test

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[^a-zA-Z\d]).{8,}$

Username (alphanumeric)

Validation

Example: john_doe.99

Test

^[a-zA-Z][a-zA-Z0-9._-]{2,29}$

Hashtag

Parsing

Example: #WebDev

Test

#[a-zA-Z][a-zA-Z0-9_]*

Twitter/X handle

Parsing

Example: @utiloom

Test

@[a-zA-Z_][a-zA-Z0-9_]{0,14}

YouTube video ID

Parsing

Example: youtube.com/watch?v=dQw4w9WgXcQ

Test

(?:youtu\.be\/|youtube\.com\/watch\?v=)([a-zA-Z0-9_-]{11})

Emoji (Unicode range)

Parsing

Example: Hello 😀 World

Test

[\u{1F600}-\u{1F64F}\u{1F300}-\u{1F5FF}\u{1F680}-\u{1F6FF}\u{2600}-\u{26FF}]

Whitespace only

Validation

Example: \t\n

Test

^\s+$

Positive integer

Validation

Example: 42

Test

^[1-9]\d*$

Decimal number

Validation

Example: -3.14

Test

^-?\d+\.\d+$

Scientific notation

Validation

Example: 6.022e23

Test

^-?\d+(?:\.\d+)?[eE][+-]?\d+$

Data URI

Format

Example: data:image/png;base64,iVBOR...

Test

^data:[a-zA-Z]+\/[a-zA-Z0-9.+-]+(?:;[a-zA-Z0-9-]+=\S+)*;base64,[A-Za-z0-9+/]+=*$

About this tool

Use a curated pattern library when you need a starting regex quickly instead of retyping common validation expressions from scratch.

Regex Pattern Library is useful when you need a common starting pattern quickly rather than inventing one from scratch. It helps with frequent needs like email, URL, phone, and ID matching, especially when the goal is to adapt a baseline pattern instead of designing a regex from zero.

Includes common patterns for email, URL, UUID, slug, and date matching.
Searches by use case, pattern, or example value.
Lets you copy patterns instantly for reuse in forms, APIs, and scripts.

How to use Regex Library

Browse the library, pick the closest matching pattern, and then test it against your real sample input before using it in production. Treat the examples as starting points rather than universal truth, because validation rules often need to be narrowed or expanded for your specific context.

When this tool is useful

Includes common patterns for email, URL, UUID, slug, and date matching.
Searches by use case, pattern, or example value.
Lets you copy patterns instantly for reuse in forms, APIs, and scripts.

Practical tips

Why people use this tool

People search for regex examples because they want a head start, not an abstract tutorial. A good pattern library page gets them to a usable baseline quickly and makes it easy to continue into testing and refinement.

Related search intents

regex pattern library, common regex examples, validation regex patterns, regex cheat sheet, pattern examples for regex.

Frequently asked questions

Are these patterns ready to copy into code?

Yes. The patterns are shown in a copy-ready form so you can use them directly or adapt them further.

Is this meant to replace a full regex tester?

No. It complements a tester by giving you strong starting patterns to copy and refine.

Are the regex patterns provided in a specific flavor like PCRE or JavaScript?

All patterns in the library use JavaScript-compatible regex syntax by default, but most are also valid in PCRE, Python, and Go since they avoid engine-specific features like lookbehind length limits.

Can I test a pattern against sample input before copying it?

Yes. Each pattern card has a 'Test' button that opens the Regex Tester tool with the pattern pre-loaded, where you can type or paste sample strings and see match highlights in real time.

How often are new patterns added to the library?

The library is updated regularly with community-requested patterns. If you need a pattern that is not listed, you can suggest it and it may appear in a future update.

Related tools

Keep the workflow moving

These tools are the closest next steps based on category, keyword overlap, and popular workflow paths.

Developer

Regex Tester

Test regex patterns and flags in the browser.

SEO

Slug Generator

Create SEO-friendly URL slugs from text.

Developer

ASCII Table

Look up ASCII codes and characters quickly.

Developer

Base64 Decoder

Decode Base64 strings into plain text.