The upload portal has a strict 400kb limit, but my scanned four-page application PDF is over 2 MB. How can I compress the file that much without making the text totally unreadable?
I ran into this with scanned contracts and got the biggest reduction by rescanning in grayscale at 150 dpi, using black and white for plain text, then saving as an optimized PDF. If it is still over 400 KB, I would check whether the portal accepts separate page uploads, since four readable scanned pages may not fit that limit in one file.
If you scanned it as color, try rescanning in black and white or grayscale at a lower dpi like 150, that alone can shrink it a lot before you even compress anything. What did you scan it with?
If you can rescan it, switch the color mode to black and white or grayscale and drop the resolution to 150 dpi. Color scans at 300 dpi are usually what blow up the file size. At 150 dpi, four pages of text should easily drop under 400kb while staying readable.
The quickest fix is usually to rescan rather than squeeze what you’ve got. Set the scanner to greyscale or black and white at 150 dpi, not colour at 300, and four pages often land under 400kb by themselves. On a Mac, Preview’s export with the Reduce File Size filter helps too. Keep your original scan somewhere safe first.
Try PDFcap, open the file and use the compress tool, then choose a lower quality until it’s under 400kb. That usually keeps the text readable on four pages.
Avoid cranking the scanner dpi way up, it just makes huge files. Not sure if Mac version has the same slider.