How can I reduce the dimensions of a PDF?

[oxband]

I have a PDF I exported from Keynote and it exported files which are 26.67x15

I need to shrink those down cause right now the file is WAY too big to send to people. If I "Reduce File Size" it in preview, the image quality is horrible and there are lots of photos.

Any suggestions? Ideally, to shrink the file size to 11x8.5 or even better to reduce the PDF size from 500 MB without sacrificing quality. I've spent two hours on this. I'm going nuts.

 

[organicCPU]

To scale the page size of a PDF down, I'm using Adobe Acrobat Pro 2017. Inside the Acrobat Pro DC 2015 preflight profiles there is a profile for PDF corrections that can be adapted to ones needs. I was searching some time ago for a different (free) solution, but couldn't find something else that worked for me for publishing.

However, you can also scale to a non professional PDF with Preview.

Just select Print (Cmd + p) -> choose another paper size (or first create the size that you like) -> select to scale to paper size -> then use the PDF dropdown menu to Save as PDF. In Preview, in general, most of ones PDF editing needs to be printed out to another file and confusingly not to be saved by the Save command.

Reducing a PDF size further is something that really depends on the individual PDF and what you consider as "without sacrificing quality". IMO, the best results for a smallest possible file size is by writing directly to a small PDF file. Maybe Keynote is not perfect to do so, because it's an app for presentation and not primarily a publishing app. If you could upload a typical single PDF page, it would be much easier to give advice.

You could try to create an individual filter in ColorSync-Utility and apply that, but this didn't work well for me in the past. Again, personally I'm using Acrobat Pro for reducing file size ,if I don't have the source file, but there are plenty of other tools available (some of them free from time to time) that can convert images inside a PDF to a lower resolution and deleting unnecessary chunks of data. Depending on your PDF, those tools could fail, too. http://appshopper.com/search?search=PDF+Compress+Expert
Sometimes placing a PDF in some DTP app like InDesign, QuarkXpress or Scribus and writing another PDF from it is a better solution, sometimes even that fails. That's why I recommend to use a publishing app from the beginning for the most minimal PDF file size.

 

[Apple_Glen_UK]

I have a PDF I exported from Keynote and it exported files which are 26.67x15

I need to shrink those down cause right now the file is WAY too big to send to people. If I "Reduce File Size" it in preview, the image quality is horrible and there are lots of photos.

Any suggestions? Ideally, to shrink the file size to 11x8.5 or even better to reduce the PDF size from 500 MB without sacrificing quality. I've spent two hours on this. I'm going nuts.

I found a website called Sejda a little while ago and I use it at work loads. There are lots of tools, it's easy to use - and it's free! The website address is: www.sejda.com

Hopefully that might help.

 

[Apple fanboy]

I have a PDF I exported from Keynote and it exported files which are 26.67x15

I need to shrink those down cause right now the file is WAY too big to send to people. If I "Reduce File Size" it in preview, the image quality is horrible and there are lots of photos.

Any suggestions? Ideally, to shrink the file size to 11x8.5 or even better to reduce the PDF size from 500 MB without sacrificing quality. I've spent two hours on this. I'm going nuts.

Have you thought about using a file sharing option like Dropbox or we transfer?
Or if in the same area and on apple devices, airdrop.

 

[mikzn]

Just select Print (Cmd + p) -> choose another paper size (or first create the size that you like) -> select to scale to paper size -> then use the PDF dropdown menu to Save as PDF.

I second the print menu 'Save as PDF" in preview as organicCPU suggested

I use this often to increase or reduce page dimensions to a standard "US letter" size in preview for printing as PDF

You can do the same thing in Acrobat Pro - print menu < "Shrink oversized pages" or scale the print file

You can probably do in Keynote too - print < Keynote< Page Attributes