Compress images in the PDF
Reduce image resolution
Convert images to JPEG instead of PNG where possible
Remove unnecessary pages
Delete embedded fonts not needed
Subset embedded fonts
Remove metadata and hidden data
Flatten annotations and form fields
Optimize the PDF with a PDF editor
Save the PDF as a reduced-size or optimized version
Use a smaller file format before converting to PDF
Avoid scanning at very high resolution
Convert color images to grayscale if acceptable
Use PDF compression tools or online compressors
Recreate the PDF with lower-quality export settings