The Regex Tester is an indispensable tool for developers, data analysts, and anyone working with string manipulation and validation. It provides a real-time environment to test and debug your Regular Expressions (RegEx) using JavaScript's regex engine. As you type your pattern, the tool instantly highlights all matches within your test string. You can also specify flags (like `g` for global search or `i` for case-insensitivity) and view detailed information about each match found, including capture groups and their indices.

1. Enter your regular expression pattern in the "Regular Expression" input field. Do not include the leading/trailing slashes.
2. Enter any flags you wish to use (e.g., `g`, `i`, `m`) in the "Flags" input field.
3. Provide the text you want to test your pattern against in the "Test String" area.
4. As you type, the "Highlighted Matches" box will update in real-time, showing all parts of your test string that match the pattern.
5. The "Match Information" box will list each match found, along with its index and any capture groups.
6. If your regular expression is invalid, an error message will be displayed, helping you debug the pattern.