Regex Tools & Patterns

Test, debug, and learn regular expressions with free browser-based tools. Browse a library of 15+ common regex patterns with explanations and examples.

Tools

Regex Tester

Test regex patterns with live matching & flags

Regex Explainer

Get human-readable regex explanations

Regex Pattern Library

Email RegexURL RegexIPv4 RegexPhone Number RegexDate RegexUsername RegexHex Color RegexPassword RegexCredit Card RegexUUID RegexIP Address RegexHTML Tag RegexSlug RegexWhitespace RegexNumber Regex

Common Regex Patterns

EmailUrlIpv4PasswordPhone UsDate IsoHex ColorUuidHtml TagCredit CardSlugMac AddressJwtSemver

Python Regex Snippets

Python regex match

JavaScript Regex Snippets

JavaScript regex match

Error Solutions Related to Regex

CORS ErrorGit Merge Conflict

Regex guides & blog articles

Best Regex TesterRegex CheatsheetHow to Write Regex

Related Discovery Pages

All ToolsAll JS Methods

Related Hubs

Developer ToolsText ToolsJSON ToolsEncoding Tools

About Regex Tools

Regular expressions are one of the most powerful — and most confusing — tools in a developer's arsenal. DuskTools makes regex approachable with a live tester that highlights matches in real time, a plain-English explainer that breaks any pattern into human-readable steps, and a curated library of battle-tested patterns for emails, URLs, IP addresses, UUIDs, credit cards, and more. Each pattern page includes the raw regex, annotated explanations, example matches and non-matches, and copy-ready snippets for JavaScript, Python, and other popular languages. Whether you are validating form input, parsing log files, or building a URL router, starting from a well-documented pattern saves hours of trial and error. The tools also link to language-specific regex snippets so you can jump straight to working code in Python or JavaScript. For tricky edge cases, the error solutions section covers common pitfalls like CORS misconfigurations and merge conflicts that often surface alongside regex work. Everything runs client-side, so your test strings and patterns stay private.