Regex Tester — free online tool

Test JavaScript regular expressions against sample log lines or form validation strings before deploying code.

Useful when you want a quick answer without pasting sensitive data into random chat bots.

How to use Regex Tester

Type your JavaScript regular expression in the Regex Tester pattern field.
Paste sample text in the subject input—log lines and form values work well.
Run test to highlight matches and capture groups.
Adjust flags (global, case insensitive) if the card exposes them, then retest.

Practical tips

Build the pattern incrementally—test each group before combining the full expression.
Remember this uses JavaScript regex; PCRE-only features like lookbehind vary by engine.
Escape literal dots and slashes, or they will match far more than you intended.

Limitations

Regex Tester runs on text in your tab only—there is no cloud save, version history, or collaboration. Copy results before closing the page.

Privacy & data

We do not run a database on this static site. Text and generated output exist only in your tab until you close or refresh the page.

Frequently asked questions about Regex Tester

Is the Regex Tester free on Webtoolshop?

Yes. There is no sign-in and no paywall on this page. We may show advertising on some layouts to cover hosting.

Can I use the Regex Tester on a phone?

Yes for light tasks. Very long pasted text, huge images, or multi-megabyte PDFs are easier on a laptop with more memory.

Why did the Regex Tester fail or look wrong?

Try a smaller file, fewer pasted characters, or an updated browser. Extensions that block scripts or downloads sometimes interfere—test in a private window if results never appear.

Does Webtoolshop store text I paste into the Regex Tester?