How to get a PDF under an upload portal’s size limit

Before you touch a tool, look at three facts: the file’s current size, the portal’s cap, and the page count. Divide the cap by the page count to get a per-page budget.

• A 12-page scan that has to fit in 2 MB gives you about 170 KB per page.
• A 30-page scan that has to fit in 5 MB gives you about 170 KB per page as well.
• A 4-page scan that has to fit in 5 MB gives you about 1.25 MB per page, which almost any scan already meets.

Leave yourself some margin. If the cap is 2 MB, aim for 1.8 MB, because some portals count a megabyte as 1,000,000 bytes and others as 1,048,576, and a file that is “2.0 MB” in your file manager can still be rejected.

The budget tells you what kind of problem you have. A colour scan of an A4 page at 300 dpi is about 2480 × 3508 pixels. Saved as a high-quality JPEG inside a PDF, that page can easily weigh 1 MB or more. Getting it to 170 KB means fewer pixels and a lower JPEG quality. Getting it to 600 KB usually needs only a modest pass.

Open the file and try to select a sentence. If you can, the text is real text. Those pages are usually small already, and their weight is in fonts and any photos placed on them. If you cannot select anything and every page looks like a photograph of paper, it is a scan, and scans are where the bytes are.

This matters because PDF Compress works on the images inside the PDF. It re-encodes photos and scans as JPEG and can lower their pixel size. It does not touch real text, fonts, or vector drawings. A 40-page contract exported from a word processor at 3 MB is mostly fonts and text, and no preset will take it to 1 MB. A 40-page phone scan at 30 MB is almost entirely images and can shrink a great deal.

1. Run Balanced on a copy

Open PDF Compress, drop the PDF, and leave the preset on Balanced (JPEG quality 62, images capped at 1500 pixels on the long edge). Click Compress and download. Your browser saves a new file ending in .compressed.pdf; the original is not changed.

Read the summary line. It shows the before and after size and how many images were re-encoded. If the new size is under your target, open the file, zoom to the level a reviewer would use, and check that small print, signatures, and stamps are still legible. If they are, you are done.

2. If it is still too big, step down in a controlled way

Do not jump straight to the lowest settings. Change one control at a time and compress the original again, not the already-compressed copy. Re-compressing a compressed file stacks JPEG losses for little extra saving.

• Lower the max image edge first. On an A4 page, a 1500 pixel long edge is roughly 128 pixels per inch. 1200 pixels is about 100 per inch, which is still readable for typed text at normal zoom.
• Then try the Strong preset (quality 42, 1000 pixel edge). On A4 that is about 85 pixels per inch. Typed documents usually survive. Handwriting, small tables, and fine print may not.
• If you need a middle point, set quality around 50 with a 1200 pixel edge by hand.

Each run tells you the new size, so you can stop at the first setting that fits.

3. When compression is not enough, reduce the page count

If Strong still leaves you over the limit, the honest answer is that the content is bigger than the cap allows at a readable quality. Look at whether the portal needs every page. Blank backs from a duplex scan, instruction sheets you were not asked to return, and duplicate pages all count. Use PDF Split in range mode to keep only the pages that matter, for example 1-3,5-9, then compress that shorter file.

Some portals allow several uploads in the same field or a second “supporting documents” field. In that case, split the document into two parts that each fit, and name them clearly, such as bank-statement-part1.pdf and bank-statement-part2.pdf.

4. Rescan if you can

If you still have the paper, a better scan often beats any amount of compression. Most scanner apps and multifunction printers let you pick resolution and colour mode. For typed documents, 150 to 200 dpi in grayscale is usually enough to read and produces far smaller pages than 300 dpi colour. Keep colour only for pages where colour carries meaning, such as a stamped seal or a photo ID.

A 9-page rental application scan is 14.2 MB, and the portal’s limit is 5 MB. The budget is about 550 KB per page, with margin about 500 KB.

• Balanced on the original brings it to a size that depends on the scan, so run it and read the summary. Suppose it reports 6.1 MB: close, but over.
• Instead of compressing the 6.1 MB file again, go back to the 14.2 MB original, keep quality at 62, and set the max edge to 1200. Suppose that gives 4.3 MB.
• Open the result. The payslip figures and the signature on page 7 are readable. Upload.

The numbers in your case will differ, because the result depends on how the scan was made. The method is the point: measure, change one setting, compress from the original, check, stop.

• Photos of documents taken with a phone camera. A 12-megapixel photo of a single page is around 4000 × 3000 pixels, much more than a reader needs. Cropping and using a scanner app before making the PDF saves more than compressing afterwards.
• Merging before compressing. If you combine several files with PDF Merge, it does not matter much whether you compress before or after, since each image is processed separately. It does matter that you check the final merged file against the cap, because that is the one you upload.
• Black-and-white fax-style scans. Some scanners save pure black-and-white pages with an encoding called CCITT or JBIG2. These are already compact, and PDF Compress skips them. If such a file is too big, the cause is usually page count, not the encoding.

Documents sent to application portals tend to be the sensitive kind: IDs, bank statements, payslips, medical letters. PDF Compress runs in your browser, so the file is processed on your device and is not uploaded to QuickConvert. The only place the document goes is the portal you choose to send it to. The broader trade-offs are covered in how to protect your privacy when you use online file tools.

Why does the portal reject a file that my computer says is under the limit?

Some systems measure in decimal megabytes and some in binary ones, and some count the total of several files in one field. Aim about 10 percent under the stated cap.

Will compressing make the text blurry?

Real text in the PDF is not re-encoded, so it stays sharp. Text that is part of a scanned image is pixels and does soften at low quality, which is why you should check small print after each run.

The summary says no images were re-encoded. What now?

The file is mostly text, fonts, or an image encoding the tool skips. Remove pages you do not need with PDF Split, or export the document again from the program that created it.

Can I compress a password-protected PDF?

No. Remove the password in a PDF reader that already has it, then compress the unlocked copy. QuickConvert never asks for the password.

Is there a file size limit for the tool itself?

Yes, each PDF must be 80 MB or smaller, because the whole file is processed in the browser’s memory.

For background on why some PDFs shrink and others do not, read how to reduce a PDF’s file size without turning pages into pictures. When you have the numbers ready, open PDF Compress.