Regex Cheatsheet

Quick reference of common regular expression patterns

Regex Cheatsheet

Filter snippets

Matches: 8

Matching Snippets

Email address
^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$
Basic email pattern for validation.
hello@example.com

HTTP/HTTPS URL
https?:\\/\\/[^\\s/$.?#].[^\\s]*
Matches URLs with http or https.
https://example.com/docs

UUID v4
\\b[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}\\b
Matches UUID version 4.
3fa85f64-5717-4562-b3fc-2c963f66afa6

IPv4 (loose)
\\b(?:\\d{1,3}\\.){3}\\d{1,3}\\b
Basic IPv4 pattern without range validation.
192.168.0.1

Hex color
#(?:[0-9a-fA-F]{3}){1,2}\\b
Matches 3 or 6 digit hex colors.
#ff6b6b or #fff

ISO date
\\b\\d{4}-\\d{2}-\\d{2}\\b
Matches dates in YYYY-MM-DD.
2025-01-31

URL slug
^[a-z0-9]+(?:-[a-z0-9]+)*$
Lowercase words separated by hyphens.
dev-utility-hub

Signed number
-?\\d+(?:\\.\\d+)?
Integers or decimals with optional minus sign.
-42 or 3.14

Email address

Basic email pattern for validation.

^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$

hello@example.com

HTTP/HTTPS URL

Matches URLs with http or https.

https?:\\/\\/[^\\s/$.?#].[^\\s]*

https://example.com/docs

UUID v4

Matches UUID version 4.

\\b[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}\\b

3fa85f64-5717-4562-b3fc-2c963f66afa6

IPv4 (loose)

Basic IPv4 pattern without range validation.

\\b(?:\\d{1,3}\\.){3}\\d{1,3}\\b

192.168.0.1

Hex color

Matches 3 or 6 digit hex colors.

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

#ff6b6b or #fff

ISO date

Matches dates in YYYY-MM-DD.

\\b\\d{4}-\\d{2}-\\d{2}\\b

2025-01-31

URL slug

Lowercase words separated by hyphens.

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

dev-utility-hub

Signed number

Integers or decimals with optional minus sign.

-?\\d+(?:\\.\\d+)?

-42 or 3.14

How to use

1. Paste your input or choose a sample.

2. Adjust the options and run the tool.

3. Copy or share the output.

Use Cases

Quickly finding starter patterns while building validators

Sharing common regex snippets with teammates

Common Mistakes

Copying patterns without adjusting for the specific context (URL vs HTML vs logs)

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