Regex Tester OnlineTest and debug regex patterns instantly with private, in-browser matching.

Regular Expression

Flags:g globali case insensitivem multiline

Test String

0 matches

Common Patterns

Quick Reference

Character Classes

. Any character
\d Digit (0-9)
\w Word character
\s Whitespace
\D Non-digit
\W Non-word

Quantifiers

* 0 or more
+ 1 or more
? 0 or 1
{n} Exactly n
{n,} n or more
{n,m} Between n and m

Anchors

^ Start of string
$ End of string
\b Word boundary
\B Non-word boundary
| OR operator
() Capture group

Overview

Test and debug regular expressions instantly with a free, online regex tester that runs entirely in your browser. See real-time matches, highlights, and capture groups as you iterate on patterns without leaving your editor.

Developers use regex to validate inputs, parse logs, and transform text, but small mistakes can be painful to track down. This tool keeps everything client-side for privacy and speed, so your test data never leaves the browser and results appear instantly with no registration. Iterate quickly until your pattern is solid.

Whether you are building validators, scrapers, or data pipelines, a visual tester shortens the feedback loop. Tune your expression until the exact substrings are highlighted, then copy the final pattern into your codebase with confidence.

Live match highlighting with capture groups.
Toggle common flags to test global or case-insensitive matches.
Copy the final regex pattern in one click.
Fast, private in-browser processing for sensitive text.

How to Use

Build patterns iteratively and confirm matches before adding them to production code.

Enter your regex pattern and select the flags.
Paste sample text to test against the pattern.
Review matches and captured groups in real time.
Copy the final regex when it behaves correctly.

Common Use Cases

Regex shines when you need flexible text validation or extraction across large datasets.

Validating emails, UUIDs, or custom identifiers.
Parsing server logs or error messages quickly.
Extracting query parameters from URLs.
Cleaning up CSV or multiline text data.

FAQ

Which regex flavor is supported?

The tester uses JavaScript RegExp syntax, matching what you use in the browser. That keeps results consistent with frontend code.

Is my test data private?

Yes. All matching happens locally in your browser. Nothing is transmitted or stored.

Can I test flags like global or multiline?

Yes. Toggle the common flags to match your runtime behavior. The output updates instantly.