Supported MPP files

FormatPeek reads standard Microsoft Project .mpp files and displays the scheduling information the parser can extract.

FormatPeek Editorial TeamPresented by Claire Bennett, editorial personaPublished September 10, 2026 · Updated September 10, 2026

File requirements

• The filename must end in .mpp.
• The maximum upload size is 30 MB.
• The file must not be password protected or corrupted.

Version compatibility

MPP is a proprietary binary format that has changed across Microsoft Project releases. FormatPeek is designed to handle commonly used MPP files, but unusual custom fields or features from a particular Project release may not display exactly as they do in Microsoft Project.

What is displayed?

When present, FormatPeek displays tasks, WBS hierarchy, dates, durations, progress, milestones, dependencies, critical status and resource assignments. It is a viewer and does not modify or save the original project.

Other formats

XML, MPX, XLS, XLSX, PDF and image files are different formats and cannot be uploaded as MPP files.