Regex Library
Browse and copy standard regular expression patterns for emails, URLs, IP addresses, dates, and common formats.
Run tool
The Regex Library provides ready-to-use regular expression patterns for sixteen standard data formats and syntax checks. You can look up specific patterns or browse the entire collection in one view. Supported categories include email addresses, web URLs, US phone numbers, IPv4 and IPv6 network addresses, ISO dates, 24-hour timestamps, hexadecimal color codes, credit card numbers, and US ZIP codes. The reference collection also includes patterns for strong passwords, URL slugs, standard UUID strings, Base64 encoding strings, HTML tags, and hardware MAC addresses. Entering a recognized category name retrieves the exact regular expression syntax along with a concise explanation of its structure. Leaving the category field blank displays the complete list of sixteen patterns sorted alphabetically. This reference tool is designed for quick lookup and copy operations during software development, data validation scripting, or form configuration. The tool serves as an expression catalog rather than an interactive string tester.
Instructions
- Enter an optional category name such as email, uuid, or ipv4 into the category field.
- Leave the input blank if you want to inspect all available regular expressions at once.
- Select the run button to retrieve the requested patterns.
- Review the pattern syntax and explanation in the result panel, then copy the expression for your project.
Examples
- Looking up the email pattern: Enter 'email' in the category box and submit the query to receive the standard email matching regular expression and explanation.
- Browsing the full catalog: Leave the category field completely empty and run the tool to view all sixteen predefined patterns, covering UUIDs, IP addresses, dates, and other standard formats.
FAQ
What happens if I enter an invalid category name?
If you enter a category name that is not in the library, the tool reports that the category was not recognized. You can clear the field to browse all supported categories.
Does this tool test my input strings against the regular expression?
No. This tool functions as a pattern lookup library. It returns the syntax and description of standard expressions rather than running live match tests on custom sample strings.
Are category lookups sensitive to capitalization?
No. Category lookups ignore letter case, so entering EMAIL, Email, or email produces the same pattern details.