Regex Tester Online — Free Tool

Develop and test Regular Expressions (Regex) in real-time against custom sample texts with visual highlighting.

Pattern

Tip: Enable g to find all matches.

Test string

Matches

12 matches

Showing up to 12 matches

Highlighted preview

Paste your test string here. Try a pattern like: \b\w+\b

Match list

0–5

Paste

6–10

your

11–15

test

16–22

string

23–27

here

29–32

Try

33–34

35–42

pattern

43–47

#10

50–51

#11

52–53

#12

55–56

Privacy note: All processing happens entirely in your browser. No data is sent to our servers.

About this tool

Regex Tester is a fast, browser-based developer utility. Develop and test Regular Expressions (Regex) in real-time against custom sample texts with visual highlighting. To use it, paste or upload your input in the tool above, choose any options (like formatting style, separators, or output type), and copy or download the result. Because it runs in your browser, it’s ideal for quick edits, previews, and conversions without installing extra software. Common use cases include cleaning up data before sharing, converting formats for a spreadsheet or API, validating content before deployment, and generating outputs you can paste directly into your codebase. If you handle sensitive data, prefer tools that run locally in your browser—this helps reduce the risk of uploading private content to a server.

How to use

Enter or upload your input in the tool panel above.
Adjust any options if provided.
Copy or download the output.

This page is available at /tools/regex-tester.

Related keywords

regex testerregular expression testerregex matchregex flagsregex tool

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FAQ

What is Regex Tester?

Regex Tester is an online tool that helps you develop and test regular expressions (regex) in real-time against custom sample texts with visual highlighting.

How do I use the Regex Tester?

Add your input in the tool panel, adjust options if available, then copy or download the output.

Is this tool free?

Yes—this tool is free to use.

Does it run locally in the browser?

Most tools are designed to run in your browser. If a tool uploads files to a server, it should say so in the UI.