Introducing Regex Tester | Tools.Town Blog

Regex Tester is now live on Tools.Town — a developer tool to write, test, and debug regular expressions against sample text, with live match highlighting, capture group tables, all standard flags, and an inline quick-reference guide.

Write your pattern, paste your test string, and see every match highlighted in real time.

What Does It Do?

Live Matching

Matches are highlighted in the test string in real time as you type your pattern.

Capture Groups

A table shows every match with its named and unnamed capture group values — great for extraction patterns.

Quick Reference

An inline cheat sheet covers character classes, anchors, quantifiers, and groups — no docs tab needed.

Regex Tester uses JavaScript regex syntax (ECMA-262) — compatible with Node.js, browsers, and most modern regex engines.

How It Works

Write pattern

Type your regex in the pattern field. Choose flags (g, i, m, s, u) with the toggle buttons.

→

Paste test text

Enter sample text in the test area. Matches are highlighted as you type.

→

Inspect groups

The match table shows all captures. Hover over a highlighted match to see its group details.

Why We Built It

Writing regex is an iterative process — you tweak the pattern, test it, find edge cases, tweak again. Doing this in code means write, save, run, read output — a slow loop. Regex Tester makes the loop instant: pattern and test string on the same screen, matches visible in real time. The capture group table eliminates the guesswork about which group number maps to which part of the match.

Try It Now

Free Tool

No sign-up In-browser

Regex Tester

Write and test regular expressions with live match highlighting, capture group tables, and an inline quick reference.

Live match highlightingCapture groups tableAll flags (g, i, m, s, u)Quick reference

Test Regex

See all developer tools — JSON Formatter, JWT Decoder, and more.

Frequently Asked Questions

What regex flavor does it use?

JavaScript regex (ECMA-262). This is compatible with most modern regex engines and covers the vast majority of practical use cases.

Can I test capture groups?

Yes. Named and unnamed capture groups are displayed in a table showing each match and its group values — very useful for extraction patterns.

Does it support multi-line mode?

Yes. All standard flags are available: g (global), i (case-insensitive), m (multiline), s (dotAll), and u (unicode).

AI Text Summarizer

Go Premium

Introducing Regex Tester — Now Live on Tools.Town