Inspired from Microsoft Edge browser tab previews feature, Notepad++ developer has added document peek feature to version 7.4 and is available for download with a lot of improvements and bug fixes. The feature is enabled by default in Notepad++ 7.4. By hovering the mouse over any inactive tab you can able to preview the document. And Notepad++’s peeking on the tab can be disabled by unchecking ‘peek on tab’ under ‘Document Peeker’ in MISC Preferences.