Use “Save As” or “Export” and choose a smaller file size or “Optimize PDF”
Reduce image resolution before creating the PDF
Compress images inside the PDF
Remove unnecessary pages
Delete unused fonts and embedded fonts
Flatten annotations, forms, and layers
Convert color images to grayscale if color is not needed
Use a PDF compressor tool
Re-save the PDF with a lower quality setting
Remove embedded multimedia and attachments
Crop extra white space and margins
Split large PDFs into smaller files
Use OCR only when needed and avoid storing unnecessary hidden text
Avoid scanning at very high DPI
Choose “Standard” or “Smallest File Size” when exporting from Word, PowerPoint, or similar apps