Zoven

Regex Tester

Test regular expressions with live matching online

What is the Regex Tester?

The regex tester works like this: it tests regular expressions live against sample text, highlighting matches and groups, with a pattern explanation and common recipes. Everything happens on your device - the input never leaves your tab unless the tool clearly states it performs a server-side lookup.

How to use the Regex Tester

1. Paste the input (code, data or query).
2. Run the operation - formatting and validation are instant.
3. Read any validation message before trusting the output.
4. Copy the result into your project.

Features

• Instant client-side formatting and validation
• No telemetry on your data
• Copy-ready output with proper escaping

Common mistakes to avoid

• Using the wrong input dialect (JSON vs JSON5, cron 5 vs 6 fields)
• Copying output without checking escaping

Examples

Input	Result
/\b[\w.]+@[\w.]+\.\w{2,}\b/g	Highlights every email in the sample text, capture groups itemized

Best used for

• Getting a reliable answer for regex tester without installing an app
• One-off tasks done in under a minute from any device
• Checking results before committing them to something important
• Working on a phone where desktop software is unavailable

Privacy

All parsing and transformation happens locally in this tab - your code and data are not sent anywhere.

Frequently asked questions

Which regex flavor?

JavaScript (ECMAScript) - lookahead/behind supported; .NET or PCRE-only syntax like \K will fail here.

Why is my regex catastrophically slow?

Nested quantifiers like (a+)+ backtrack exponentially. The tester aborts long runs so the page stays responsive.

How do I read the highlighted groups?

Each coloured span in the sample text is one capture group - hovering or the group list shows the exact substring it captured, which is the fastest way to debug a pattern before it ships.

Which regex flavour does the tester use?

JavaScript's own engine - what you test here behaves identically in browser code and Node. Patterns written for PCRE or Python may need small syntax adjustments.

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