Can I reduce a PDF file without affecting its quality?

[Dataqix]

I have several PDF documents that take up too much storage space, and I want to make them easier to share. I am looking for a reliable method to understand how to make a file size smaller while maintaining the original text, images, and formatting. Does PDF compression work well for documents containing multiple images? Also, are there any free online compressors that are safe and easy to use for everyday document management?