How to reduce PDF file size

When a PDF is too big to send, the fix depends on what is making it heavy — almost always images.

Compress the images

Re-encoding scanned or photographic pages at a sensible quality is the single biggest win, often cutting size by more than half.

Downsize oversized images

An image at camera resolution wastes space on screen. Scaling it to the size actually displayed shrinks the file a lot.

Remove what you do not need

Delete blank pages and drop unused attachments before saving.