Common Regex Patterns Library

About this tool

A searchable library of ready-to-use regular expressions for common tasks like matching emails, URLs, IP addresses and dates. Copy and adapt them.

Privacy

This tool runs entirely in your browser. Your data is processed locally and never uploaded to a server.

How to use this tool

1. Search for the pattern you need, like email, URL, IP address, phone number, or date.
2. Open the matching regex entry and read the pattern, what it matches, and any notes about edge cases.
3. Copy the regex string into your editor or tool and adapt it to your data, delimiters, or language.
4. Test the pattern against a few real examples before using it in production.

Step by step, what happens

1. The tool lets you browse a library of common regular expressions instead of writing one from scratch.
2. Each entry shows a ready-to-use pattern, a short explanation, and a simple example of what it should match.
3. You can search by task, compare similar patterns, and copy the one that fits your needs.
4. After copying, you should adjust flags, anchors, or strictness based on the target format in your app.

Worked example

You need to find a basic email pattern for validating a sign-up form.

Input: user@example.com

1. Search the library for the email pattern entry and copy the ready-made regex.
2. Use the pattern in your validator or test it against the sample input.
3. The sample value matches the email pattern, so it should be accepted by a basic regex check.

Tips and common mistakes

• Treat these patterns as starting points, not final proof that an input is valid. Email and URL regexes are especially easy to make too strict or too loose.
• Check whether you need a fully anchored match or just a find-in-text match before copying a pattern.
• Be careful with pattern variants for the same task, since a simple email regex and a strict one can behave very differently.
• Always test copied regexes against real good and bad examples from your own app.

Frequently asked questions