Regex Tester is a free, browser-based tool built for developers who need to write and debug regular expressions without switching to a desktop app or an unfamiliar CLI.
Type a pattern, add flags, paste your test string, and every match — including capture groups — is listed instantly.
How to use the Regex Tester
- Type your regular expression pattern into the Pattern field.
- Add any flags you need — g for global, i for case-insensitive, and so on.
- Paste the text you want to test into the Test string box.
- Every match is listed instantly below, including any capture groups.
Why use FreeToolsNets's Regex Tester?
- 100% free, with no usage limits and no account required.
- Everything runs locally in your browser — nothing you type is uploaded or stored on a server.
- Works on desktop, tablet and mobile in any modern browser.
- No installation, no plugins, and no ads blocking the tool itself.
- Part of FreeToolsNets's Developer & Data Tools collection.
Frequently asked questions
Which regex flavor does this use?
It uses JavaScript's native RegExp engine, the same one built into every modern browser.
Can I see capture groups?
Yes — each match row shows its capture groups alongside the full match text.
Is this tool free to use?
Yes, completely free on FreeToolsNets, with no sign-up and no limits.
Is my data sent to a server?
No. Everything runs locally in your browser using JavaScript — nothing you enter is uploaded anywhere.
Does it work on mobile?
Yes, the widget is fully responsive and works on phones, tablets and desktops.