Regex Tester
Test a regular expression against your text, with flags and a live count of matches. Runs entirely in your browser.
How to use
Pick a ready-made pattern or type your own, set flags, and enter test text. Matches are highlighted inline and listed with their capture groups, the match count updates instantly, and you can preview a find-and-replace using $1/$& — all privately in your browser.
FAQ
What can I use Regex Tester for?
Regex Tester is useful when you need to test a regular expression against your text, with flags and a live count of matches. Runs entirely in your browser. It is meant for quick checks, everyday workflows and practical tasks where a fast browser-based result is enough.
How do I use Regex Tester correctly?
Paste the code, data, URL, token or text you want to inspect, then choose any formatting or validation options.
What input does Regex Tester need?
Use the fields shown in the tool and keep the input close to the real case you want to solve. If the page includes examples or presets, start with those to understand the expected format.
What result does Regex Tester give me?
The tool returns formatted output, decoded data, parsed information or validation feedback for your development workflow. In most cases the output updates instantly and can be copied, downloaded or used as a reference for your next step.
How accurate is Regex Tester?
Developer tools are designed for quick inspection, formatting and local checks. Always test production code in your real environment.
Is my data uploaded when I use Regex Tester?
The tool is designed to run in your browser, so ordinary inputs are processed locally unless a page explicitly states that it needs an online lookup.
What common mistakes should I avoid with Regex Tester?
Avoid assuming formatted or decoded output is production-ready. Validate edge cases in your own runtime before shipping.
What related tasks can Regex Tester help with?
Regex Tester is intended for use cases related to "regex tester" and nearby needs such as "regular expression tester". For best results, follow the labels, examples and options on the page.
What are the limits of Regex Tester?
It is optimized for common web use, not unlimited batch processing or every edge case.
When should I double-check the output from Regex Tester?
Double-check the output before pasting it into production code, configuration files or automated workflows.