🔍 Regex Tester

What is a Regular Expression (Regex) Tester?

A Regular Expression (Regex) is a powerful tool for searching, extracting, and replacing patterns in strings. It is used in every area of development: validating email formats, extracting phone numbers, parsing URLs, analyzing logs, and more. This tester highlights matched portions of the test string in real time as you type, and counts the number of matches. It supports the major flags — g (global), i (case-insensitive), m (multiline), s (dotAll) — and includes a cheat sheet of common patterns for emails, phone numbers, URLs, hex colors, and more.

Common Use Cases

How to Use

1. 1
   Enter Pattern

   Type your regex directly in the /pattern/ field, or click any item in the cheat sheet sidebar to instantly load a common pattern like email, phone number, or URL.
2. 2
   Select Flags

   Toggle g (global search), i (case-insensitive), m (multiline), or s (dotAll — dot matches newlines) to fine-tune matching behavior.
3. 3
   Type Test String

   Enter your test text in the middle editor. Matched portions are instantly highlighted in yellow and the total match count updates in real time.
4. 4
   Review & Apply

   Check the matched token list in the result area below, then copy your validated pattern directly into JavaScript code using test(), match(), or replace().

Frequently Asked Questions