Compress images in the PDF
Reduce image resolution
Convert images to grayscale
Remove unnecessary pages
Delete embedded fonts
Subset fonts instead of embedding full fonts
Remove unused objects and metadata
Optimize PDF for web viewing
Use PDF compression software
Save the PDF with a smaller file size setting
Convert scanned pages to lower DPI
Flatten annotations and form fields
Reduce transparency and effects
Use a different PDF format or export setting
Split large PDFs into smaller files
Recreate the PDF from source with lighter settings