My thesis is a 120-page scanned document and the submission portal rejects anything over 500 KB, so I’m stuck with a file that comes out several megabytes. The pages are mostly black-and-white text, and I need it to be readable, so I’m not sure how far the size can drop before it becomes unusable. It’s due Friday and I’m working on a regular Windows laptop.
Honestly, 500 KB for 120 pages is really tight, like a few KB per page, so first double-check the portal limit isn’t actually MB. Biggest win is rescanning in pure black-and-white (1-bit, not grayscale) at 200 dpi instead of color. If it still won’t fit, ask if you can split it into parts.
I had a similar issue with massive patient record scans. Getting 120 pages under 500 KB is very tight, but what worked for me was using PDFcap:
- Upload your file to PDFcap.
- Select strong compression and switch the colours to pure black-and-white.
- Download and zoom in to make sure the text is still legible.
Getting 120 scanned pages under 500 KB is nearly impossible. Try opening the scan in Word to extract the text and save it as a fresh PDF. Avoid using greyscale if you must re-scan, as it massively bloats the file size. I learned the hard way with my bakery invoices that pure black and white is the only option.
Had the same thing last month getting a scanned handbook under a size limit. For black and white text scans, scan at 300 dpi max and save as black and white or grayscale instead of color, that alone cuts size dramatically. If your scanner software lets you choose a lower dpi like 200, try that too, text usually stays readable down to 150 to 200 dpi.
@SneakySteel 150 dpi is my fallback if 200 still overshoots, and I’d skip grayscale entirely, that’s what bloated the scans on my old laptop.
@emily.7 I agree, 150 dpi and 1-bit black-and-white is worth trying, but 500 KB for 120 pages is still unusually tight. I’d first confirm the portal really means KB, then keep a backup and ask whether a text-extracted PDF or split upload is allowed.
For 120 scanned pages, 500 KB is probably a portal typo or meant for a single attachment, because readable scans usually cannot get that small. I would first ask the submission contact to confirm the limit, then rescan at 150 dpi in black-and-white, run OCR, and save with CCITT Group 4 compression. Acrobat’s PDF Optimizer can do this, but keep the original and check every page before uploading.
If you still have the originals, rescan at 200 dpi in black and white (not grayscale), that’ll cut size dramatically. Otherwise open the file in something like Nitro or an online compressor and target around 150 dpi for the text pages. I learned this the hard way when a similar file ballooned past 20 MB.
@wallabies the rescan advice is what saves me at work. I set our office scanner to black and white at 200 dpi before scanning anything text-heavy, and the file size drops far more than tweaking the PDF afterwards does. If the scan is already done, Word can re-save the pages as a fresh PDF, though you lose the scanned look.
first id convert it to black and white not grayscale. that cuts scanned text a lot. pdf24 is free on windows and has a compressor. 500kb for 120 pages is tight so you might need lower dpi, not sure how readable it stays