Regex Tester

Enter a regex pattern and test string. All matches are highlighted in real-time. Supports flags (g, i, m, s) and shows match groups.

Regex Pattern

//g

gglobaliignore casemmultilinesdotAll

Test String

How to use Regex Tester

Test and debug regular expressions with live highlighting.

Enter your regular expression pattern in the top field.

Set the flags you need (g, i, m, s) using the toggle buttons.

Type your test string below. All matches highlight in real time and match groups are listed.

Is Regex Tester free to use?

Yes, Regex Tester is 100% free with no account required and no usage limits.

Is my data private?

Yes. Processing happens entirely in your browser. We never see, store, or transmit your input data.

Does Regex Tester send data to a server?

No. All processing happens locally in your browser. Your data is never uploaded or transmitted anywhere.

Can I use Regex Tester with large files?

Yes, though very large files (100 MB+) may be slower depending on your device. For most development use cases, performance is instant.