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Online Regex Tester (JavaScript Regular Expressions)

Write a regular expression, paste your text and see live highlighted matches, captured groups and replacement results. JavaScript syntax with g, i, m, s, u flags.

🔗 Direct link sahlify.uk/en/regex-tester/

How does it work?

Type or paste your data.
The result appears instantly.
Copy or download the result.

Why use Regex Tester?

✓ 100% free, no limits, no watermark
✓ No sign-up, no install
🔒 Files processed locally: full privacy
📱 Works on desktop, tablet and mobile

Frequently asked questions

Which syntax is used?

JavaScript (ECMAScript) regular expression syntax, close to Python and PHP.

What does the g flag do?

g (global) finds all matches instead of stopping at the first one.

Which syntax is used?

JavaScript (ECMAScript) syntax, close to PHP, Python and Java for common cases.

Can I test a replacement?

Yes, with captured groups $1, $2…

Is this tool really free?

Yes, 100% free, with no sign-up, no watermark and no usage limit.

Are my files safe?

Yes. Processing happens directly in your browser: your files are never uploaded to a server or stored.

When to use it

The regex tester lets you validate an email, phone number or postcode, extract data from text, clean a file or fine-tune a redirect rule before going live.

Our tips

💡 Test your regex on several valid and invalid examples.
💡 Add ^ and $ to validate a whole string.
💡 Example: Moroccan mobile number ^(\+212|0)[67]\d{8}$.