Open an MS Project file

View MPP opens Microsoft Project files in a browser: drop an .mpp, Project .xml, .mpx, .mpd or Primavera .xer and the schedule is drawn as an interactive Gantt chart - hierarchy, dependency arrows, the critical path, non-working days. Every value is read out of the file as Project saved it, and nothing is recalculated.

How it works

1. Drop the file. An .mpp saved by any modern version of Microsoft Project, a Project .xml, or the older .mpx and .mpd exports. Primavera .xer files open too. Nothing is installed and you are not asked to register.
2. It is read, not kept. The file goes straight into a reader that pulls out the schedule and is gone the moment that finishes. It is never written to disk.
3. The plan appears. Usually in a second or two. From there it is an ordinary interactive chart: scroll it, search it, collapse the parts you do not care about.

What you can actually read

A schedule is not just a list of dates, and a viewer that shows only names and dates is useless for the question you are normally trying to answer - which is some version of what is late, and what does it drag with it. Everything below comes out of the file:

• The task hierarchy. Phases contain tasks contain subtasks, to whatever depth the planner used. Collapse a phase to see the shape of the project on one screen, expand it when you need the detail.
• Dependencies. Arrows between bars, covering all four link types, so you can follow what waits on what instead of guessing from the order of rows.
• The critical path. Tasks with no slack are highlighted - these are the ones where a day lost is a day lost for the whole project.
• Non-working days. Shaded from the project calendar, so a bar that looks two days too long usually turns out to be spanning a weekend.
• Everything on a single task. Click any bar: start and finish, duration, percent complete, its predecessors, the people assigned to it and any notes the planner left.

There is also a search box over the task table, and four zoom levels - day, week, month and quarter - because a two-year programme and a two-week sprint need very different scales to be legible.

What it will not do

This is a viewer, deliberately. You cannot drag a bar, change a date or re-plan anything, and that is the point: nothing you do while reading can alter the plan its owner is working from. If the schedule is wrong, the conversation belongs with the person who sent it - not with a copy you quietly edited.

It also never recalculates the schedule. The critical path, the summary dates and the calendars are read out of the file exactly as Microsoft Project saved them, so what you see is what the planner sees, not a second opinion produced by different arithmetic. Nothing is rescheduled, no date is derived and no task is moved.

A chart you operate, not a document you page through

Most free viewers for this format do something subtly different from what they appear to promise: they turn the plan into pages. You scroll a picture of the schedule, a page at a time, and download it as a PDF. That is a rendering of the plan, and it is genuinely useful when what you need is to print it or forward it. It is close to useless for the question people actually arrive with, because you cannot ask a picture anything.

Everything on this page is the opposite of that, and you can check all of it in the time it takes to read this paragraph. Change the time scale between day, week, month and quarter and watch a two-year programme collapse to one screen. Fold a phase away to see the shape of the project without its detail. Click any bar and get its dates, progress, predecessors, resources and notes. Follow a dependency arrow to the task it points at. The critical path is already highlighted, so the tasks where a lost day is lost for good are visible before you look for them.

There is also no daily quota here. Viewers that ration you to a handful of files a day are making a reasonable business decision, but it lands badly on the person this exists for: you rarely get sent one schedule, you get sent a revision, then a corrected revision, then the version someone else edited, and running out of attempts halfway through that is exactly the wrong moment.

Common questions

Do I need Microsoft Project installed?

No. The file is read on the server and drawn as a chart in your browser. Nothing is installed on your machine, and no licence is involved.

Is my file stored anywhere?

No. The file is read in memory and never written to disk or to a database. If you are not signed in, nothing about the plan survives the request - reloading the page loses it, which is why there is nothing to delete later.

Which versions of .mpp open?

Files saved by Microsoft Project 2003, 2010, 2016 and 2021 all open through the same reader, along with Project XML (MSPDI) files. The format generation is detected automatically.

Can I edit the schedule here?

No. This is a viewer: it shows what the file already contains and never changes dates, durations or dependencies. Nothing you do here can alter the plan the sender holds.

How large a file can I open?

Up to 10 MB, with or without an account. A plan with well over a thousand tasks fits comfortably inside that. Pro raises the limit to 50 MB.

Does it work on a Mac or on Linux?

Yes. Everything happens in the browser, so the operating system does not matter. This is the usual reason people arrive: Microsoft Project has no macOS version at all.