How to Compress a PDF file (Mac)
PDFs often can be quite large, making it difficult to e-mail or upload the files. It may be necessary to compress the document to make the file-size smaller.
To compress a PDF file:
1.) Open your PDF using the Preview application
2.) Choose File > Export
3.) Choose Reduce File Size from the Quartz Filter pop-up menu
This process compresses the images in the file. The compressed images look the same as the originals when viewed onscreen, but may appear to be of lower quality when printed.