Keynote Conundrum

I’m preparing a presentation which consists almost exclusively of photographs with captions… no videos, no animations, very little text, simple transitions. I’m using Keynote ’09 version 5.1 on the Mac as a glorified 35mm slide carousel.

The file is 188 MEGAbytes.

Which is absurd. There are 70 slides. I manually shrunk all the source images to 1024×768 in Acorn before pasting them into Keynote. So if the whole darned thing were stored as uncompressed 1024x768x24bit images, it’d be “only” 165 megabytes. Since compression exists, it should be a lot smaller.

Keynote’s “Reduce file size” option says “can’t be reduced any further.” Doing a “Save as…” under a new name results in the identical 188 MB.

Well, what the heck. Disk space is cheap, so I shouldn’t sweat it, right? Even though I still have in my possession several working external hard disks which are significantly smaller than 188 MB.

But… I want to use this presentation with Keynote on my iPad.

  • Can’t email a file that size.
  • Can’t use Dropbox (crashes).
  • Can’t use (crashes).
  • Can’t use iDisk (don’t have enough space free, and I suspect it would crash as well).
  • Can’t use a USB drive (Steve Jobs thinks I don’t need one on my iPad).
  • Can’t use iCloud (I’m not a developer and don’t have it yet).
  • Inconvenient to use iTunes and a USB cable (my iPad is synced to my home Mac, and I was trying to do this at the office).

So I really do need to shrink it down.

Exporting it to PDF results in a filesize of 65 MB… a 2/3rds reduction.

To add insult to injury, I tried exporting it to PowerPoint then re-importing it as Keynote. That results in a 56 MB Keynote file! Which happily transfers over Dropbox. And even with 70% fewer bits, even the detailed images look great on the iPad screen.

So I’ve solved my immediate problem, but I still don’t understand what the heck Keynote is doing with all that disk space! Transmitting secret steganographic copies of WikiLeaks? Any ideas?


  1. Can’t say for sure, but if you want to Terminal that sucker you can go into the file (Keynote files should just be directories like most Apple file formats) and run du -h -d 1, which should tell you how much each top level directory/file takes up. Rinse and repeat to find out where all that disk space is going.

  2. Stephen,
    Apple removed the default setting of saving keynote 09 files as packages.
    If you go into the preferences and select “Save new documents as packages” this brings back the useful feature.
    You can then right click on your keynote file and “Show Package Contents” this allows you to view the actual images you have added to your presentation and check size. I’ve seen instances where files where deleted from the presentation but not from the actual file.

    I’d be glad to take a look at the file. I live in extreme graphic/animation keynote / powerpoint world. 🙂

    – Ivan

  3. Conundrum solved by a tip from @pfreet. Apparently, Keynote pastes images as uncompressed TIFFs, and then refuses to compress them, even when executing “Reduce file size.” So you have to export everything to JPG, then reimport the JPGs. Have done the first half, and the folder of 70 images is only 9 megabytes! That sounds about right.

    I love Keynote, but this is really clumsy. Maybe in that hypothetical future update where the features of Keynote-for-Mac and Keynote-for-iOS are harmonized?

  4. Stephen,
    Also try the method outlined in this article for saving documents to the ipad or iphone.
    It may save all the manual tiff to jpeg conversion done otherwise.
    It’s at least worth a try

  5. Just to provide the final number for this: exported the presentation from Keynote as a folder full of 1024×768 JPGs using the “50% – Good” setting. Then I imported them into Keynote one by one (tedious). Ultimate file size: 9 MB. Visually indistinguishable from the 188 MB original. Wow. Not often that I see 95% compression!