History State Viewer is a free Chrome add-on developed by JungleHam. As the name suggests, it is a tool that allows users to view the value of history.state. With just a click, this add-on runs the "history.state" console command and displays the result in a small popup window.

The main purpose of History State Viewer is to provide users with a quick and convenient way to check the state of their browsing history. When the console command returns "null," indicating no state is found, the add-on displays the message "Console: Output: No state found." This simple and straightforward feature can be incredibly useful for developers and users who need to keep track of the state of their browsing history.

Overall, History State Viewer is a handy tool for Chrome users who want to easily access and monitor the value of history.state. With its intuitive interface and straightforward functionality, this add-on is a valuable addition to the arsenal of developers and users alike.