What is an NBK file? An .NBK file is a data format that usually stores backup archives or digital notebook content. Because many different software applications use the .NBK extension, the exact structure of the file depends on the program that created it. Commonly, .NBK files are backup archives for note-taking apps like Noteful, MyScript Nebo, and Notability. In other cases, they act as application data files for Tomboy or legacy software like Circus Ponies NoteBook. Other Uses for NBK Files Beyond note-taking, the .NBK extension is used for a NovaBACKUP Job File created by NovaStor. It is also used for CNC controller backups by Heidenhain, digital video recorder backups for DVR systems, and spectral data files in Thermo Nicolet OMNIC software. Additional uses include backup jobs for Prosoft Engineering and SMART Notebook files. How to open NBK files? To open an .NBK file offline, you must know which application created it. If it is a Noteful backup, you can import it directly into the app. If it is a NovaBACKUP Job File, you need NovaStor software. An .NBK file can internally be a ZIP archive, an XML document, or an SQL database, meaning standard unzipping tools or text editors can sometimes extract the contents. Inspect and view NBK files online Since the .NBK extension has multiple possible meanings, viewer.online/nbk analyzes .NBK files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. Summary In conclusion, because .NBK files use the known ZIP format, viewer.online/nbk can safely open and display them online, eliminating compatibility problems.