Useful for
- Format, validate, encode, decode, inspect, or generate developer-friendly values.
- Troubleshoot copied snippets before adding them to a project.
- Prepare quick examples for documentation, testing, support, or debugging.
Regex Tester
Test regular expressions against text and see matches, groups, and replace results.
Matches: 0
Tool guide
How to use Regex Tester
Regex Tester gives you a focused way to handle one small task quickly. Test regular expressions, see matches and groups, and try find-and-replace. It is free to use, requires no login, and is built for quick checks when you need a practical result.
Example
For example, use Regex Tester while checking an API response, preparing a test value, inspecting a URL, or cleaning up code-adjacent text.
Good to know
Most developer utilities run in your browser. Avoid pasting secrets, API keys, passwords, or private production data into any online tool.
How it works
The regex tester evaluates a regular expression against test text in your browser. It shows matches with positions, captured groups, and supports replace mode with global and case-insensitive flags.
The tool uses the JavaScript RegExp engine to test, match, or replace text.
Practical examples
- Extract email addresses from text with (\w+)@(\w+\.\w+).
- Test a phone number pattern like \(?\d{3}\)?[-.\s]?\d{3}[-.]?\d{4}.
- Use replace mode to redact or reformat matched patterns.
Common mistakes
- Remember to escape backslashes in the pattern field. Write \d not d.
- The global flag (g) changes how match results are returned. Without g, only the first match is shown with groups.
Questions
Does this use the same regex engine as my programming language?
It uses the JavaScript regex engine. Other languages like Python, PHP, or Java may have slightly different regex syntax.
Are my regex patterns sent anywhere?
No. All regex testing runs in your browser. No text or patterns leave your device.