Online Regex Tester
Online regex tester to match, search and replace text with regular expressions.
What is this Regex tester?
Regex (regular expression) is used for matching and replacing text patterns. This online regex tester lets you quickly experiment with patterns, see matches in real time, and debug flags and capture groups.
Key features
- Live match preview while you type.
- Support for common flags like global and ignore case.
- Replacement preview to test substitution patterns.
- Reference area for common patterns (if available).
Use cases
- Extract fields from logs.
- Validate user inputs.
- Batch replace text in large documents.
- Parse URLs, timestamps and other structured text.
Frequently Asked Questions
What is a regex tester?
A regex tester lets you enter a regular expression and some sample text, then shows you which parts of the text match and how capture groups behave.
Is my data uploaded?
Most tools run locally in your browser. For tools that require network requests, the UI will indicate it.
Why is the result unexpected?
Check your pattern, flags and test text. Small differences in anchors, quantifiers or multiline mode often change which matches are found.
Is it free?
Yes. This regex tester is free to use and does not require an account.