Regular Expression (Regex) Tester

Test regular expressions in real-time against sample text with flag support and match highlighting.

How It Works & Processing Standards

Test regular expressions in real-time against sample text with flag support and match highlighting.

Your input data is never sent to any server and is securely processed on your device.

Current Limits

  • Maximum input length: 100,000 characters

Regular Expression (Regex) Tester is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.

How to Use Regular Expression (Regex) Tester

  1. 1
    Enter Pattern & FlagsInput your regular expression pattern and optional flags (e.g. gi).
  2. 2
    Provide Sample TextPaste the multiline text you want to test against.
  3. 3
    Review MatchesView matching count, matched spans, and capture details.

Common Use Cases

  • Validating email and telephone input patterns, testing scraper expressions, and debugging code logic
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