A Keynote presentation that is too big to email or upload

A Keynote file that is too big to send is almost always carrying video: a few phone clips or screen recordings can outweigh every slide in the deck. Full-resolution photos come next, and media you trimmed in Keynote still sits in the file at full length. Keynote’s own File, Reduce File Size handles much of it. For a video-heavy deck, shrink the clips before they go in, or send a PDF or a movie export instead of the .key file itself.

Work out what is making it big

Keynote stores a full copy of everything you drop into a slide. It does not link to the original, and it does not scale anything down to fit what the slide shows. That leads to a few predictable culprits:

• Video. At 4K, a minute of iPhone video takes well over a hundred megabytes; the iPhone’s Settings, Camera, Record Video screen shows the figure for each setting. Screen recordings made at Retina resolution are large too.
• Photos from a camera or phone. A photo shown at postage-stamp size on a slide is still stored at full resolution.
• Trimmed media. If you trimmed a movie or audio clip with Keynote’s own controls, the parts you cut are still saved in the file, in case you change your mind.
• Masked and cropped images. Masking hides part of a photo on the slide; the hidden part is still there.
• Skipped slides. Media on slides marked Skip still counts in full, even though those slides never appear when you play the deck.

To see the size of any one clip before it goes in, select it in Finder and press Command-I.

Use Reduce File Size first

Keynote has a built-in tool for this, and it is the right first step:

1. Duplicate the presentation (File, Duplicate) so you have an untouched copy.
2. In the copy, choose File, Reduce File Size.
3. The dialog shows the current size and an estimate after reduction. It offers to scale down large images, to drop the trimmed-away parts of movies and audio, and to convert movies to a lower quality.
4. Choose the options you want and apply them.

The options that save the most are usually the movie ones. Removing trimmed portions costs nothing you can see. Lowering movie quality is a real trade: on a projector it rarely shows, but on a large display in a small room it can.

If the estimate is still too high, the deck probably contains one or two very large clips, and the next section is the better fix.

Shrink the videos before you add them

Reduce File Size works on the whole deck at once. Shrinking the clips yourself gives you control over each one, and it is the only fix that also helps the next time you build a deck from the same footage.

A useful rule is to size each clip for how it will be shown. A clip that fills the slide on a 1080p projector gains nothing from being 4K. A clip in a quarter of the slide can be smaller still. Bitrate, resolution and frame rate explains which of those to cut first.

Manatee makes this a matter of picking a number. Open it, choose Shrink, drop in the clip, and type the size you want in MB; Manatee finds the quality that fits and writes a new file next to the original, which stays untouched. Then, in Keynote, delete the old clip from the slide and drag the smaller one into its place. Builds or actions attached to the old clip need setting up again on the new one.

If a clip also refuses to play properly in the slide, convert it first: how to convert a video to MOV for Keynote covers that. Manatee runs entirely on the Mac, with nothing uploaded. It is free for 24 hours with every feature, then $9 once.

One limit to know: Manatee works on the videos and PDFs you put into or get out of Keynote. It does not open, repair or convert .key files themselves.

Send something other than the .key file

Ask what the recipient actually needs. Often it is not the editable deck.

• To read or print it: choose File, Export To, PDF. Pick Good for Image Quality, and leave presenter notes out unless they are wanted. A PDF has no video, so it is often a fraction of the size. If it is still too large, Manatee’s Shrink mode handles PDFs the same way it handles video: name a size, get a copy that fits.
• To watch it: choose File, Export To, Movie, and pick 1080p or 720p rather than 4K. The export plays the deck with its timings and animations. Shrink it afterward if it has a hard size limit to meet.
• To edit it: keep the .key file, reduce it as above, and send a link through iCloud Drive instead of an attachment. Email attachment size limits by provider lists how much each mail service will actually carry.

Keep the next deck small from the start

A few habits stop the problem before it starts:

• Trim clips in QuickTime Player (Edit, Trim) before adding them, rather than in Keynote, so the cut parts never enter the file.
• Resize photos to roughly the size they will be shown at before inserting them. How to get a photo under 200 KB shows the built-in ways to do that on a Mac.
• Keep one folder of prepared, right-sized clips for decks you rebuild often.
• Check the size in Finder after adding each large clip, rather than discovering the total at the last minute.

The same approach applies to slide decks and documents from other office apps; this guide to making office files smaller covers those.

Questions

Will Reduce File Size make my photos look worse? Only if they were larger than the slide ever shows them. Images are scaled down to a size that still looks sharp on the slide, and on a projector the difference is rarely visible. Work on a duplicate so you can compare.

Why is my presentation still large after deleting a video? Check for other slides using the same clip, including skipped slides, and for a soundtrack added to the whole presentation. Then run Reduce File Size on a duplicate to see what else it finds.

Can I send the deck to someone who does not have Keynote? Export a PDF for reading. If they need to edit it, File, Export To also offers other slide formats; check the result before sending, since some effects and fonts change on the way.