Regex Tester - Free Online Tool | PivaBox

Test regular expressions in real-time with match highlighting

How to Use Regex Tester

1. Enter your regular expression pattern in the Pattern field (without surrounding slashes)
2. Set the Flags (e.g., g for global, m for multiline, i for case-insensitive)
3. Type or paste your test text — matches will be highlighted in real time, and the match list shows each match with its position

Frequently Asked Questions

Is Regex Tester free?

Yes, PivaBox Regex Tester is completely free to use. There are no charges, subscriptions, or hidden fees.

Are my patterns uploaded to a server?

No. All regex testing happens entirely in your browser using JavaScript's built-in <code>RegExp</code> engine. Your patterns and test data never leave your device.

What regex syntax is supported?

This tool uses JavaScript's native RegExp syntax, which supports common patterns like character classes (\d, \w, \s), quantifiers (+, *, ?, &#123;n,m&#125;), groups and captures ((...), (?:...)), anchors (^, $), lookaheads ((?=), (?!)), and alternation (|). For a complete reference, consult the MDN Regular Expressions guide.