Use a PDF compressor tool
Reduce image resolution
Compress embedded images
Convert images to JPEG instead of PNG when possible
Remove unnecessary pages
Delete unused objects and metadata
Flatten transparent elements
Remove embedded fonts not needed
Subset embedded fonts
Optimize for web viewing
Save the PDF as a smaller file size preset
Convert scanned pages to grayscale
Lower the quality of images before exporting
Remove comments, annotations, and form data
Split large PDFs into smaller files
Recreate the PDF with lower export quality