Powerpoint file sizes

Was dealing with a big Powerpoint presentation (PPT) file.

In the older PPT format, 6063 Kb.

When zipped, 4826 Kb. Not a bad saving given the number of pictures in it.

Here’s the interesting thing: in PPTX format: 3293 Kb.

Remembering that PPTX and other Office Open XML formats (DOCX, XLSX etc) do their compression on the file as a whole, not the individual componenets, so this is an interesting result.

Perhaps the old binary format is inherently less efficient/compressible than the new XML format.

Mind you, another big PPT I tried it with didn’t compress down as much; the PPTX was about the same size as the ZIPped PPT, so it obviously depends on the exact content

1 thought on “Powerpoint file sizes

  1. Chris Till

    Bear in mind Office 2007/2010 finally take into account the way non-computer literates paste images into their documents.

    People have always pasted the biggest pictures known to man into their documents, resized it within Word to be a small logo in a header or whatever, and then wondered why their document was now multiple-MB in size. Naturally the entire picture is still being stored within the document, doh, resize it BEFORE you paste!

    Whereas Office 2007/2010 will actually physically resize the graphic – suddenly a 2.5MB document becomes 50KB as it should be.

    My favourite of course is that when opening attachments in Outlook 2010 – when Outlook creates a temporary copy of the attachment for you to open it, finally, flags it as read only. YAY – I’ve been submitting requests for this since the Office 95 beta. A day has never gone by when someone hasn’t opened a spreadsheet or document someone sent them via e-mail, made changes, closed it, and then wondered where on Earth that save went (eg – nowhere, it was only a temporary copy). Amazing they can create an entirely new operating system that copies another OS to absolute phenomenal detail and depth, yet they take 15 years to take notice of a feature someone’s been sending direct to their doorstep and causes end-users incredible pain.

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