Regex101

Free online tool — no sign-up required

Regex101 is the ultimate online tool for building, testing, and debugging regular expressions. It supports PCRE, JavaScript, Python, Golang, and Java regex flavors. Get real-time match highlighting, detailed explanations of each regex component, and a handy quick reference. Essential for any developer working with text patterns.

This tool is interactive — turn on JavaScript to use it.

How to Use Regex101

  1. Choose regex flavor — Select your programming language — JavaScript, Python, PHP, Go, or Java.
  2. Write your regex — Type your regular expression in the pattern field.
  3. Add test strings — Paste or type the text you want to match against.
  4. View matches — See real-time highlighting of all matches with capture groups.
  5. Read explanations — Check the detailed breakdown explaining each part of your regex pattern.

Regex101 — Frequently Asked Questions

Is Regex101 free?

Yes, Regex101 is completely free with no account required. Creating an account lets you save and share patterns.

What regex flavors are supported?

PCRE (PHP), ECMAScript (JavaScript), Python, Golang, Java, and .NET regex flavors.

Can I save my regex patterns?

Yes, create a free account to save, organize, and share your regex patterns with a unique URL.

Does it explain regex syntax?

Yes, the explanation panel breaks down each component of your regex in plain English.

Can I generate code from regex?

Yes, Regex101 can generate code snippets in multiple programming languages using your regex pattern.

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