Regex Tester & Explainer

Test regular expressions with real-time match highlighting, named groups, and plain-English explanation of each part.

Free Always No Account Needed 100% Client-Side
//
flags: /g/
2 matches
Contact us at hello@example.com or support@editingtools.tech for help.
#MatchStartEndGroups
1hello@example.com1431#1: hello#2: example.com
2support@editingtools.tech3560#1: support#2: editingtools.tech
Advertisement

How to use Regex Tester & Explainer Online

  1. 1
    Input Data or ParametersPaste your input string, code payload, or select parameters into the editor.
  2. 2
    Instant Local ComputationThe tool processes your request in real-time inside your browser using client-side JavaScript.
  3. 3
    Copy or Export OutputCopy the formatted result to your clipboard or download the output payload instantly.

About this tool

Regular expressions are powerful patterns for matching, searching, and manipulating text. Writing and debugging them can be tricky — this tool makes it visual and interactive.

Paste your regex and test string, and matches are highlighted in real-time. The tool shows every match, capture group, and named group in a structured table. Hover over any match to see its exact position (start/end index).

The explanation panel breaks down each token in your regex into plain English — for example, \d{3}-\d{4} is explained as "exactly 3 digits, a literal hyphen, exactly 4 digits".

Supports all JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode), and d (indices).

Advertisement

Frequently Asked Questions

What regex flavor does this use?
JavaScript (ECMAScript) regex, which is compatible with most modern programming languages and supported natively in browsers.
How do I use named capture groups?
Use the syntax (?<name>pattern). For example, (?<year>\d{4}) creates a group named 'year'.
What does the 's' flag do?
The 's' (dotAll) flag makes '.' match newline characters as well, which it doesn't by default.
How do I match a literal dot?
Escape it with a backslash: \. — without the backslash, '.' matches any character.

Related Tools

String Escape

Escape and unescape strings for JavaScript, JSON, HTML, SQL, and regex. Handle special characters safely.

Text Counter

Count words, characters, sentences, paragraphs, and reading time. Keyword density analysis included.

Diff Checker

Compare two texts side-by-side with highlighted differences. Supports plain text and smart JSON-aware diffing.

Case Converter

Convert text between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, Title Case, and more instantly.