Best PDF compressors for scans and upload limits

A PDF compressor is only a good fit if the resulting document still does what you need. Our pick for a scanned upload is CozyToolz Compress PDF. It gives you three levels and processes the document on your device. For a document that already contains searchable text or interactive elements, start by looking at an approach that can keep the PDF structure.

Compare compression approaches

Option	Best fit	Tradeoff
CozyToolz Compress PDF	An image-heavy scan that you can check visually	Pages are rendered into a new PDF, so the result loses interactive features and selectable text.
iLovePDF	A browser upload workflow with preset compression choices	Uploading the source is part of the workflow. Verify the output for your document.
qpdf	Local command-line optimization without rasterizing whole pages	Setup takes more effort and a clean text PDF may already be small.

iLovePDF lists its compression presets. The qpdf manual documents stream and object compression options and ways to control image optimization. These are different methods, so compare what survives in your specific file.

How we would use CozyToolz on a scan

Suppose a three-page scan is 4 MB and the upload form allows 2 MB. Remove any pages that the recipient did not request. Then run Medium on the cleaned file. Check both the new file size and the most important small print. If it is readable and under the limit, there is little reason to go further.

If the result is still too large, retry Strong from the same input. The comparison is fairer when both attempts start from the same document. If the PDF has a digital signature, needs selectable text, or includes an interactive form, use the original until you know the recipient accepts a changed copy.

Measure success beyond file size

Write down the original size, the output size, and the number of pages. Test links and search if those features are important. For a scan, look closely at the parts most likely to lose detail: a serial number, a faint stamp, or a line of fine print. Try the finished file on the device you will submit it from.

CozyToolz is our first choice for a visual scan that needs a quick local export. If your document already has the features you need, choose the method that preserves them. See the scanned PDF walkthrough and the 100 KB checklist for smaller upload caps.