Regex Tester & Bulk Extractor
Test and debug regular expressions online with real-time match highlighting. Extract emails, IPs, URLs, and more from bulk text with built-in regex pattern library.
What is the Regex Tester & Bulk Extractor?
Built-in library of common regex patterns to extract emails, IPs, and keys from raw logs in bulk. Built for optimal performance, this tool executes client-side directly in your browser without uploading your sensitive data to external servers.
How to use the Regex Tester & Bulk Extractor
- Enter your Regular Expression pattern into the regex field and toggle desired flags (e.g., Global 'g', Case-Insensitive 'i', Multiline 'm').
- Paste or type your test string into the subject text area.
- View live color-coded match highlights and capture group breakdowns updated in real time as you type.
- Copy matched strings, group values, or formatted extraction arrays for use in your codebase.
Example: Extracting Email Addresses from Raw Text
Pattern: [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}
Test: Contact support at team@ezziwebtools.com or sales@example.org for inquiries.Match 1: team@ezziwebtools.com Match 2: sales@example.org
Matches all valid email addresses across multiline logs, emails, or scraped web documents.
Technical Guide & Privacy Assurance
Use the 'g' (global) flag when you want to extract every instance of a pattern across the entire document. Omit 'g' if you only need the first match and its capturing groups.
Frequently Asked Questions
What is a regex tester?+
A regex tester (regular expression tester) is a tool that lets you write a pattern in regex syntax and test it against sample text in real time, with all matches highlighted. It helps you debug complex patterns, verify they match what you expect, and catch edge cases before using the expression in your code.
How do I extract all email addresses from text using regex?+
Use the pattern: [a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}. This matches standard email addresses. Paste your raw text, apply the pattern, and every email address is extracted instantly. This tool includes this pattern in the built-in library so you don't need to memorize it.
What regex flags should I use?+
The most commonly used flags are: g (global — find all matches, not just the first), i (case-insensitive — match 'Hello' and 'hello' equally), m (multiline — ^ and $ match the start/end of each line), and s (dotAll — the dot '.' matches newline characters too). Most text extraction tasks use the 'g' flag at minimum.
How do I extract all URLs from a block of text?+
Use the pattern: https?://(www.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_+.~#?&/=]*). This matches both http and https URLs. The built-in URL pattern in this tool handles common edge cases including query strings and URL fragments.
What is the difference between greedy and lazy quantifiers?+
Greedy quantifiers (*, +, ?) match as much text as possible. Lazy quantifiers (*?, +?, ??) match as little as possible. For example, given <b>hello</b><b>world</b>, the greedy pattern <b>.*</b> matches the entire string in one go, while the lazy <b>.*?</b> correctly matches each tag separately. When extracting structured data, lazy quantifiers almost always give you what you expect.
Can I use this regex tester with JavaScript, Python, and other languages?+
This tool uses JavaScript regex syntax (PCRE-compatible). JavaScript regex is compatible with most modern languages for standard patterns. Python uses similar syntax but with the 're' module — named groups use (?P<name>) instead of (?<name>). PHP, Ruby, and Perl also use PCRE. The built-in pattern library generates patterns tested to work cross-language for common extraction tasks.