Which regex flavor is supported?

The tester uses JavaScript regex syntax, including common flags such as g for global, i for case-insensitive, and m for multiline. Patterns that work here will also work in browsers and Node.js.

What do the capture groups show?

Parts of the pattern wrapped in parentheses appear as separate captured groups for each match. This makes it easy to see exactly which chunk of text each part of your expression extracts.

Can I use lookaheads and named groups?

Yes, the tool supports modern JavaScript features including lookaheads and named groups. Test them against your sample text to confirm the behaviour before using the pattern in code.

Is my test data safe?

Everything runs locally in your browser, so your pattern and sample text never leave your device. This makes it safe to test against real data such as email addresses or phone numbers.

ToolPilotPro

Regex Tester

Test and debug regular expressions

100% Secure

All processing happens in your browser

SSL Encrypted

Your connection is encrypted

No Files Stored

Files are deleted after processing

Lightning Fast

Process files in seconds

About this tool

Test, debug, and learn regular expressions against real sample text with instant matching and live highlights for every match and capture group. Whether you are validating inputs in a form, extracting phone numbers from a text file, or building a search pattern for a project, seeing results update as you type makes it fast to iterate until the pattern behaves exactly as you want.

How to use

1Enter your regular expression pattern
2Paste or type a sample test string
3Add flags like g, i, or m if your pattern needs them
4Review the live matches and highlighted groups
5Refine your pattern and test again until it works

Pros & Cons

Pros

Free to use with no signup, watermark, or hidden charges
Processes your input entirely in your browser, so nothing is ever uploaded to a server
Simple 5-step workflow: enter your regular expression pattern, paste or type a sample test string, add flags like g, i, or m if your pattern needs them

Cons

Requires a modern browser with JavaScript enabled
Very large files may take noticeably longer to process

Features

100% free to use
No registration required
Processes locally in your browser
Works on all devices

Privacy

Your data is processed entirely in your browser and never sent to our servers. We have no access to your files or data.

Frequently Asked Questions

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Pattern

Flags

Test String

100% Secure

All processing happens in your browser

SSL Encrypted

Your connection is encrypted

No Files Stored

Files are deleted after processing

Lightning Fast

Process files in seconds

About this tool

How to use

1Enter your regular expression pattern
2Paste or type a sample test string
3Add flags like g, i, or m if your pattern needs them
4Review the live matches and highlighted groups
5Refine your pattern and test again until it works

Pros & Cons

Pros

Free to use with no signup, watermark, or hidden charges
Processes your input entirely in your browser, so nothing is ever uploaded to a server
Simple 5-step workflow: enter your regular expression pattern, paste or type a sample test string, add flags like g, i, or m if your pattern needs them