What regex flavor does this use?

JavaScript's native RegExp engine, the same one used in browsers and Node.js.

Why aren't all matches highlighted?

Make sure the global flag (g) is enabled — without it, only the first match is found.

Can I test multiline input?

Yes — enable the multiline (m) flag if you want ^ and $ to match the start/end of each line rather than the whole string.

Regex Tester

Test a regular expression against your own sample text. Matches are highlighted live, with per-match details as you type.

//g

g — globali — case-insensitivem — multilines — dot matches newline

How to Use Regex Tester

1
Type your regular expression and set any flags you need.
2
Paste sample text to test it against.
3
Matches are highlighted live as you type.

Regex Tester Features

Highlights all matches directly in your sample text.
Supports standard JavaScript regex flags (g, i, m, s, u).
Shows a clear error message for invalid patterns instead of failing silently.

Why use Tool King?

Fast

No waiting rooms or sign-ups. Most files are ready in seconds.

Private

Files are processed in memory and discarded right after — never stored or shared.

Free

Every tool is free to use, with no hidden limits on the essentials.

Frequently Asked Questions

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