Reduce File size and retain clickable links

Hello, 
I have the same issue where using the Compress a PDF > Advanced Optimization tool is removing one important link from my pdf. I will continue to test to see if I can compress it without losing the link.

I am not aware that reducing the size of a PDF would cause the links to break, I've never had that happen to me, and I have no clue as to what could cause that.

As far as the other dynamic, images are typically the easiest thing to end up being damaged when reducing the size because either: there are too many and you have to damage the images to get a smaller size, OR the images were not saved properly in the first place. 

Let me explain the last comment: ignoring the ppi for a moment, let's say you have an image that is 4000 pixels wide. If you cut that down to 2000 pixels wide, you will reduce the storage size of the image by 75%. I do not know if you have done this, but it's very common to take an image from a camera and place it into some document without regard to the actual size needed, and thereby bloating the storage size. 

My camera (a Canon 7D, m2) takes images that are 5472 pixels on the long axis. At 300 ppi, that can give you an excellent image that is 18.24 inches wide. If you place that in a standard book width (6") as is, it will be no smaller in storage size, meaning that you are wasting a lot of the storage size for each image.

I just took one of my images and save it full sized as a JPG with 80 quality. It was 5.1 MB. I took the same image and saved it to 6" at 300 ppi, it was 947 kb. Thus, with no loss of quality, it is over 4 MG of wasted space. If you set the JPG image quality to 70 (generally the lowest setting and maintain quality), the final size of the image 731*.

Since I have no idea how many images you have, you can do only so much compression before it becomes noticably bad. So, try saving your images to fit the size at the begnining of your process. 

One other area you can save on storage size is to select fonts that are common. If you are using a collection of fonts that are unique and need to be contained in the PDF, try selecting fonts that are more common and likely to be found on most computers. Yes, this does decrease your ability to be more creative, but you also have a 20 MB size limitation. 

* Note: the actual storage size of an image can vary due to the content of an image. An image of a blue sky will be much smaller than an image of grass; the former being much smaller than the later.

There are two ways to reduce the file size of a PDF file - as long as you have Adobe Acrobat Pro: File>Save as Other>Reduced Size PDF and File>Save As Other>Optimized PDF

The first one does one thing and it cannot be configured - you either like what you get, or you move to the second option, which gives you control over how the file size should be reduced. You can specify e.g. the target resolution for images, and more. Use that option, and you can configure your links to still be in the new file.