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How to get several PDFs under a 10 MB upload limit

A portal says 10 MB, your scans add up to 45. Here is what actually makes a scanned PDF big, what you can safely change, and how to check the result before you upload.

Check what the limit really measures

Some portals limit each file; others limit the total of everything you attach. If it is a total, ten 1.2 MB files already exceed 10 MB, so every file has to shrink, not just the biggest one. Also check whether the number means MB (1,000,000 bytes) or MiB (1,048,576 bytes). When unsure, treat it as MB: it is the stricter reading. See MB vs MiB.

Why scanned PDFs are large

A scanned page is usually a photograph of paper stored inside the PDF. Its size depends on resolution (dots per inch), colour, and JPEG quality. A colour page scanned at 300 dpi and high quality can be well over 1 MB. Text-only PDFs made from a word processor are usually tiny by comparison.

What you can safely change

• Resolution. Dropping from 300 dpi to about 150–200 dpi cuts size a lot and is still readable for most printed text. Very small print, stamps and seals need more care. See scan resolution.
• JPEG quality. Moderate compression is often invisible; heavy compression adds blur and blocky edges around text.
• Colour. Converting colour scans to grayscale usually saves a large share of the bytes. See grayscale for applications, and confirm your portal accepts it.
• Needless overhead. Unused resources and duplicate objects can be removed without touching what you see.

What you should not change

Do not delete pages, signatures, stamps or whole documents just to hit a number. If a set cannot fit without that, the right answer is to tell you so and show what the smallest workable limit is, or to ask the portal for a larger allowance.

How FileMending does it

You enter the exact limit. FileMending tries lossless savings first, then lowers quality step by step on whichever file costs the least visible quality per byte saved. It keeps your file names and order, shows the before and after size of every file, and warns you about pages worth checking. A free preview lets you zoom in on small print before you decide to pay.

Check before you upload

1. Open the result and look at small text, dates, stamps and signatures at full zoom.
2. Confirm the total is under the limit with some margin; a 2% safety margin is a sensible default.
3. Check the portal's own rules for accepted file types and names.

Frequently asked questions

Will compressing a PDF delete pages?

No. Reducing image resolution and quality changes how sharp pages look, not how many there are. FileMending never removes pages to reach a size.

Is a 10 MB limit per file or in total?

It depends on the portal. Check the wording. If it is a total, the sum of all your files must be under the limit.

Can I get a clear result under the limit every time?

Not always. If a set truly cannot fit without unacceptable quality loss, FileMending tells you and shows the smallest allowance that works.

Updated 2026-10-12. General information, not legal advice. Always check the requirements of the portal or office you are uploading to.