# Regex Tester

> Test regular expressions against text and see every match, locally in your browser.

Canonical: https://host-tools.com/tools/regex-tester/

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## What does this tool do?

A regular expression (regex) is a pattern for matching text. This tool evaluates a pattern
against your text and lists every match, using the same regex engine as JavaScript — so what you
see here is what you get in the browser or Node.js.

## What you get

- **Every match, not just the first.** The global flag is applied for you, so the list shows all
  occurrences in the text.
- **Whole matches only.** Capture groups are not listed: `(\w+)@(\w+)` returns
  `ana@example.com`, not the separate `ana` and `example.com`. To inspect groups, run the same
  pattern in your own code.
- **Flags**: `i` (ignore case), `m` (multiline `^` and `$`), `s` (`.` matches newlines) and
  `u` (Unicode).

## Keep in mind

Different languages have slightly different regex flavors. Results here reflect the JavaScript
(ECMAScript) engine, which covers the vast majority of day-to-day patterns.

Matching happens as you type, so a pattern with catastrophic backtracking — `^(a+)+$` is the classic
example — can freeze the tab on the wrong input. If the page stops responding, clear the pattern
field and simplify the expression.