Regex Tester

A Regular Expression Tester is a developer utility that validates and debugs Regex patterns against target text in real-time. This tool compiles your regex pattern, runs it against custom test strings, and highlights matches and capture groups instantly. Testing regex patterns is a common developer workflow for validate inputs, parsing logs, or transforming strings. Running the engine locally in your browser ensures that your proprietary patterns and sensitive test logs are never uploaded. It operates 100% client-side to prevent credentials exposure or security leaks. Additionally, the utility provides an intuitive interface with options to copy, download, or clear output strings with a single click. This streamlines daily text manipulation tasks, log parsing, and formatting workflows for developers and editors alike. For more details, explore our blog articles: Why Offline-First Developer Tools Matter and The Hidden Risks of Online Developer Tools.

Extract Emails: /[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}/g Match Phone Numbers: /\+?\d{1,4}?[-.\s]?\(?\d{1,3}?\)?[-.\s]?\d{1,4}[-.\s]?\d{1,4}[-.\s]?\d{1,9}/g Find Duplicate Words: /\b(\w+)\s+\1\b/gi

Our tester provides real-time highlighting of matches and capture groups as you type. You can toggle flags like Global (g), Case-insensitive (i), and Multiline (m) to see exactly how they affect your search results. It also provides a detailed breakdown of each match, including starting indices and lengths.

Testing your regex against large datasets? Our tool uses a local execution engine that helps you identify slow patterns before they reach your production environment. By testing locally, you also ensure that you're not leaking sensitive test data to third-party logging servers.

Debugging complex validation logic for a new feature or an internal security tool? Secure Devutils executes your regular expressions locally. We don't track your search patterns, the regex logic you build, or the test data you provide. This ensures that your proprietary algorithms remain strictly in your control.