Regex Tester & Debugger
Test and debug regular expressions with real-time matching.
Overview of regex-tester
Regex-tester is a powerful online utility designed to help developers and content creators test and validate regular expressions (regex) in real-time. Regular expressions are sequences of characters that form a search pattern, which can be used to check if a string contains the specified search pattern. This tool is invaluable for those who need to ensure the accuracy and efficiency of their regex patterns, whether for form validation, data extraction, or any other string manipulation tasks. With its user-friendly interface and comprehensive features, regex-tester simplifies the process of writing and debugging regex, making it accessible to both beginners and experienced users.
How to Use regex-tester
- Navigate to the Website: Open your web browser and go to the regex-tester website.
- Input Your Regex Pattern: In the "Pattern" field, enter the regular expression you want to test. For example, to match email addresses, you might enter
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$. - Enter Test Text: In the "Test Text" field, input the text you want to apply your regex pattern to. This could be a single string or multiple lines of text.
- Run the Test: Click the "Test" button to see the results. The tool will highlight matches in the test text and provide additional details such as the number of matches, the matched strings, and any errors in the regex pattern.
- Review the Results: The "Results" section will show you the matches found, along with any groups or captures if your regex includes them. You can also view the "Explanation" tab to get a detailed breakdown of how your regex works.
- Adjust and Iterate: Based on the results, refine your regex pattern and retest until you achieve the desired outcomes.
- Save or Share: Once you are satisfied with your regex, you can save it for future reference or share it directly from the tool.
Usage Examples
Example 1: Matching Email Addresses
Input (Pattern):
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$
Input (Test Text):
john.doe@example.com
jane_doe@work.org
invalid-email@.com
Output:
Matches:
1. john.doe@example.com
2. jane_doe@work.org
Non-matches:
1. invalid-email@.com
Example 2: Extracting Phone Numbers
Input (Pattern):
(\d{3})-(\d{3})-(\d{4})
Input (Test Text):
Contact us at 123-456-7890 or 987-654-3210.
Output:
Matches:
1. 123-456-7890
- Group 1: 123
- Group 2: 456
- Group 3: 7890
2. 987-654-3210
- Group 1: 987
- Group 2: 654
- Group 3: 3210
Example 3: Removing HTML Tags
Input (Pattern):
<[^>]+>
Input (Test Text):
<p>This is a <strong>test</strong> paragraph.</p>
Output:
This is a test paragraph.
Feature Table
| Feature | Description |
|---|---|
| Real-time Testing | Instantly see the results of your regex pattern as you type or paste text. |
| Group and Capture Support | Highlight and extract specific groups and captures from your test text. |
| Detailed Explanation | Get a step-by-step breakdown of how your regex pattern matches the text. |
| Error Highlighting | Identify and correct errors in your regex pattern with clear error messages. |
This guide should help you get started with regex-tester and make the most of its features to enhance your regex skills and efficiency.