Illustrator (and also Premiere Pro) keep creating huge files

[KC8716]

I have been using Adobe Creative Cloud software for several years and just started having an issue where no matter what I do with my files in Illustrator or Premiere Pro, they end up saving themselves as massive files.

For example, I will create a 1080px by1080px file, make all the visual elements myself, and include maybe 2 or 3 pictures that are ~3,500KB each. When I save the file either as an .ai or pdf, the size will end up being over 100,000KB. The only way I have found that works to fix it is to save it as an .ai file and select print to pdf, then the pdf file will go to a normal size. 

Additionally - I recently had a coworker ask me to do a simple cut for a training video he had recorded. All I had to do was use the razor tool to cut off the last few minutes of video. The video was 432MB unedited, when I saved my changes, and exported the file, it ballooned to over 3x its original size.

I'm not looking for suggestions on how to compress these files, I just want to know if anyone has an idea of why this is happening...thanks.

[Larry G. Schneider]

Do you use the Web & Video new document profile for your files? If so, do you delete the second artboard before saving?

[KC8716]

Sometimes I use the presets you are talking about, other times I create a custom artboard. I don't typically use more than one artboard in my files.

[Ton Frederiks]

If you save an Illustrator file with images embedded, Illustrator will uncompress the images and save them uncompressed in the file.

If you save the file with PDF compatibilty, you will save the same images again in the PDF part of the file.

[Ton Frederiks]

To make files smaller; link images instead of embedding and uncheck the PDF compatibility when saving as .ai

When saving as PDF, uncheck the Illustrator editing option and set the compression in the PDF save dialog.

Be careful, always do this on a copy because when you uncheck the Illustrator editing option, Illustrator cannot edit the resulting pdf.

[KC8716]

Thank you, I don't really ever embed my photos, they are usually always linked. I found suggestions similar to what you're describing previously, but it still ended up giving me pretty big files. I tried again with your suggestions and it only brought the file from 117,000 kb to 58,713 kb, still too big to attach to an email... it isn't a detailed file either.

[Ton Frederiks]

The PDF settings have options to compress the images with jpeg compression. Depending on what you want with the file, it can reduce the filesize a lot.