Look at clipboard contents
The clipboard is a key vehicle for communicating between web and native apps, but browser dev tools don’t make it easy to examine.
Clipboard Inspector lets you explore the kinds of data available when you paste something on a web page, or drag-and-drop something onto it. The tool also serves as a quick reference to the relevant Web APIs.
Source available on GitHub.
Related projects
UI Events Viewer
The UI Events Viewer helps you debug the events dispatched by browsers when you input text.