A client or general contractor sent you a .mpp schedule, and Windows says it can't open it. An MPP file is a Microsoft Project plan, and Microsoft does not offer a free viewer. Here are your options.
| Option | Cost | File leaves your PC? | Best for |
|---|---|---|---|
| 1. Ask for a PDF or Excel copy | Free | No | A one-time look |
| 2. A desktop MPP viewer | Free to view | No | Regular use, confidential schedules |
| 3. ProjectLibre | Free | No | If you also want to edit |
| 4. Online MPP viewers | Free | Yes, uploaded | Non-sensitive files |
| 5. Microsoft Project | Paid | No | Building and editing schedules |
Microsoft Project can save a plan as PDF, Excel or XML. If you only need to look at the schedule once, asking for a PDF is the quickest route. The downside: you get a static snapshot and can't zoom, search or filter.
A viewer app opens the original .mpp file and shows the task list, dates, dependencies and Gantt chart as the planner built it. Because it runs on your PC, the file is never uploaded – important for construction and engineering schedules that are often confidential.
Our own MPP Viewer – Gantt & Schedule Reader for Windows is free to view. It shows outline levels, durations, % complete, predecessors with lag, resources and a zoomable Gantt chart. A one-time Pro upgrade adds Excel and PDF export.
ProjectLibre is a free, open-source project management program that can import MPP files. It is a full editor, so it is heavier than a viewer, and some details (such as baselines in newer files) may import differently. A good choice if you need to change the plan, not just read it.
Several websites open MPP files in the browser. They are convenient, but you must upload the file to someone else's server, and many have file-size limits. Avoid them for confidential project data.
If you build or edit schedules regularly, Microsoft Project (a Project Plan subscription or a Project desktop license) is the full tool. Note that Microsoft Planner does not open .mpp files directly.
No. Excel can't read the MPP format. Ask for an Excel export, or open the file in a viewer that can export to Excel.
Viewers read the dates saved in the file. If the sender changed the plan without saving, or uses a different calendar, ask them to save and resend the file.
XER files come from Oracle Primavera P6, a different scheduling program, and need a viewer that supports that format.