Regex Generator

Free Regex Generator — Build Regular Expressions with Live Preview

Regular expressions are the most powerful text-matching tool in computing — but the syntax is notoriously difficult to write from memory. Whether you need a regex for Google Analytics filters, URL matching in code, log parsing, form validation, or text search, this free Regex Generator helps you build, test, and understand regex patterns with a visual builder and live preview of matches.

Select the type of pattern you need (URL match, email validation, phone number, date format, IP address, custom), configure the options, and the tool generates the correct regex syntax. Paste any test string to see which parts match in real time before copying the pattern.

For Google Analytics specifically, regex is used in view filters to include/exclude traffic, in goal URL matching, in segment conditions, and in custom report dimensions. Understanding the difference between "Contains" (substring match) and regex patterns prevents common GA configuration mistakes.

Essential Regex Syntax

Anchors. ^ matches the start of a string. $ matches the end. Use ^/blog$ to match exactly /blog, not /blog-post.

Wildcards. . matches any single character. .* matches any sequence of characters (zero or more). .+ requires at least one character.

Character classes. [0-9] matches any digit. [a-z] matches any lowercase letter. [^abc] matches any character NOT in the set.

Quantifiers. {3} matches exactly 3. {2,5} matches 2 to 5. ? makes the preceding element optional (0 or 1 occurrence).

Related Tools

• URL Rewriting Tool – Use regex patterns in Apache mod_rewrite rules.
• UTM Link Tracker – Build trackable URLs for analytics campaigns.

Frequently Asked Questions