Ridiculously Big Visio File Size

I am guessing this is a bug in Microsoft Visio 2002. I am making these large (34" x 44" on a plotter) diagrams that show the relationships of various screen shots in an application. The file was passing 15 Megabytes in size with 6 pages in the project. The save time was a few (10 or 15 maybe) seconds, and I had more pages to go.

In order make the files smaller and decrease the save times I decided to split each page into its own file. The new file was 30 Megabytes. Twice the size for only one page! At first I thought it was undo data or something along those lines. I went through a few permutations to try and make it smaller, including manually copying and pasting the page into a new instance of Visio. Still no luck.

While looking through the options I was looking at the Summary tab under File / Properties. It was set to draft quality and a preview of the first page. My first thought was that a single preview image couldn't make that big of a difference, but I decided to remove it and see what happened (since I tried everything else). The new file size was under 2 Megabytes.

Hard to imagine that the low resolution preview image could be 28 Megabytes in size. I figure there is some bogus data that got cleared out when I disabled the image. To test my theory I closed and reopened Visio and put the enabled the First Page Preview again. New file size? 30 Megabytes. Changing the Quality (of the preview) from Draft to Detailed made little difference in file size.

I disabled the First Page Preview on the original 15 Megabyte file and it dropped the size to 12 Megabytes.

Out of curiosity I added a blank page as the first page and turned first page preview back on. That made no impact in file size, it was still 2 Megabytes. I looked back at my original 15 Megabyte (now 12 Megabyte) file, and the first page in there was very sparce of screen shots, which would explain why disabling the first page preview made less of a difference.

Moral of the story: Disable Page Preview in Microsoft Visio 2002, especially if you have screen shots and/or are using large paper sizes!