Project Online is going away — how to open your exported .MPP files

Microsoft's retirement date for Project Online is September 30, 2026. Once that passes the projects stored in the service are no longer reachable, and there is no read-only period — whatever was exported beforehand is the copy of record.

If your projects were saved out through Project desktop, what you have now is a folder of .MPP files. Which raises the question that tends to arrive a few days later: what opens them? .MPP is Microsoft Project's proprietary binary, and for many teams the Project licences left on roughly the same schedule as the service.

Ingantt opens them in the browser. Upload the file or pick it from Google Drive, and the project comes back as a full interactive Gantt chart — sub-tasks, dependencies, resource assignments, milestones, baselines, and the critical path. The MS Project XML sitting next to your exports opens the same way. No licence, nothing to install, and it works the same on macOS, Linux, or a Chromebook. Opening a .MPP file takes about thirty seconds.

It's not a viewer, either — an exported plan can be re-planned, and exported back to MS Project XML for colleagues still running Project.

Worth being straight about the limits: Project Online was an enterprise PPM platform, and Ingantt does not replace the portfolio analysis, stage-gate workflows, timesheets, or OData reporting. What it replaces is the scheduling half — the plans themselves. If that's the part you need working on October 1st, there's more detail on the Project Online alternative page.