Free Regex Tester Online
Test a regular expression against a string in the browser. Example:
^[A-Z]{2}[0-9]{4}$ with AB1234.
Invalid or huge patterns are rejected. Matching is capped so a bad regex cannot freeze the tab for long.
Flags (how the pattern is applied)
| # | Match | Index | Groups |
|---|---|---|---|
| Run Test to see matches. | |||
About Regex Tester
Test and debug regular expressions online with this free regex tester. Enter a pattern with flags, paste sample text, and see matches, capture groups, and match counts highlighted in real time so you can refine the expression before using it in code. It helps with validation rules, log parsing, search and replace tasks, and extracting ids from messy text.
Regular expressions are powerful and easy to get slightly wrong. A tester that shows groups saves you from shipping a pattern that matches the whole line when you only wanted a capture. Frontend developers test email and phone patterns. Backend developers test log lines and routers. Data people extract fields from exports. Flags such as case-insensitive and multiline change results; seeing that live is faster than redeploying.
Paste representative samples, including cases that should not match. Count of matches tells you whether you accidentally matched too much. Copy the final pattern into JavaScript, a language with similar syntax, or a config file. Remember that flavors differ; this tester uses the browser engine, which is close to JavaScript regex. Python, Java, and POSIX may still need a final check in those runtimes.
Everything is evaluated in your browser, so patterns and test data stay private. Customer logs and PII in samples are not uploaded. Use this free online regex tester and regular expression debugger whenever you need live matches and capture groups with privacy.
Features
- Test a regular expression against a string
- Adjust length, format, and count to match your needs
- Copy or download generated output in one click
- Generation stays on your device
- No signup and no intentional server-side storage of tool input
How to use Regex Tester
- Choose the options for Regex Tester, such as length, format, or count.
- Generate the result in one click.
- Copy or download the output and use it in your project or account.
- Generation happens in your browser and is not stored on our server.
Suggested next steps
- Password Generator — Strong random passwords with length, case, number, symbol, and phrase options
- Random Text Generator — Generate random text using letters, numbers, and special characters
Frequently asked questions
Is Regex Tester free?
Yes. Regex Tester on Free Tool Mate is free to use in your browser. There is no paid unlock for the core tool features described on this page.
Does Regex Tester upload my data?
No. Regex Tester is designed to process your input locally in the browser. Free Tool Mate does not intentionally store tool input or uploaded files on the server.
Do I need an account to use Regex Tester?
No account is required. Open the page, use Regex Tester, and leave when you are done.
What can I use Regex Tester for?
Regex Tester covers Test a regular expression against a string. It is built for quick, private work in the browser without installing desktop software.