LINE Message Validator is a Chrome extension that allows you to validate LINE Messaging API message objects. This extension is designed to help developers ensure that their message objects adhere to the required format.

To use LINE Message Validator, simply follow these steps:

1. Input your channel access token, which can be obtained from the LINE Developer Console or through the API.

2. Input the message object that you want to validate in JSON format.

3. Click on the "submit" button, and the result will be displayed in the "result" field.

LINE Message Validator is a useful tool for developers working with the LINE Messaging API, as it helps ensure the accuracy and validity of message objects. It is a free extension available on the Chrome platform.