Regex Tester

Test and debug regular expressions with real-time matching

Read the full guide
//g
Flags:
Common patterns:

Master your Regular Expressions. Debug patterns in real-time with visual highlighting and group capture details. Perfect for validating emails, parsing logs, or cleaning data strings.

A Regular Expression (Regex) is a sequence of characters that forms a search pattern. It can be used for text search and text replace operations. It is a powerful tool available in almost all programming languages.

Form Validation

Testing patterns for passwords, phone numbers, or usernames before implementing them in code.

Data Extraction

Using capture groups to pull specific information like dates or IDs from large log files.

As you type your pattern, our tool executes the regex against the test string using the JavaScript engine. It visually maps matches and provides the start and end indices for every hit.

FlagNameEffect
gGlobalDon't stop at first match
iIgnore CaseCase-insensitive search
mMultiline^ and $ work per line

This tool uses the native JavaScript RegExp engine, ensuring that what you see here is exactly how it will behave in your web apps.

Frequently Asked Questions

Does it support lookbehind?
Yes, modern browsers now support both positive and negative lookbehind in JavaScript.

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