Most of the PDFs that fail an upload limit are scans: a few photographed or scanned pages saved as one file. The text in them is a picture, so the file is as large as the pictures. Getting under 200 KB means making those pictures smaller, and the trick is to lose resolution you cannot see rather than detail you need. Every step below runs in your browser; the file is never uploaded.
1. Check the limit and the page count first
Form notices usually say three things: the maximum size (100 KB, 200 KB, 500 KB or 1 MB are the common ones), the format (PDF, sometimes JPG), and what the file must contain. Read all three before you start, because a 100 KB limit for a one-page certificate is easy and a 100 KB limit for a ten-page mark sheet is not.
As a rule of thumb, a clean A4 scan compresses to roughly 60 to 120 KB per page at a quality that stays readable. If the maths does not work out, the fix is fewer pages or a smaller scan, not harder compression.
2. Compress the PDF
Open Compress PDF and drop the file. It stays in your browser; nothing is uploaded.
Pick Max compression. It shrinks only the pictures inside the PDF, so any real text stays sharp and searchable.
Read the new size and the percentage saved, then save the file.
Still too big? Go back and try the steps below before compressing again; compressing a compressed file a second time gains little.
3. If it is still over the limit
- Remove pages you do not need. Remove pages lets you tick the extra pages and save the rest.
- Split a long document and upload the part the form asks for; Split PDF saves each part as its own file.
- Rescan at a lower setting. 150 dpi in greyscale is plenty for a certificate; colour at 300 dpi is four to six times larger for no gain.
- If you only have a photo of the document, shrink the photo first with Compress image, then turn it into a PDF with JPG to PDF. A photo straight from a phone camera is 3 to 6 MB; the same page at 1,200 pixels wide is under 150 KB.
4. Keep a copy that is still readable
Open the compressed PDF and zoom in on the smallest text, a seal or a signature. If it has turned to blocks, go back a step: Balanced instead of Max, or a slightly larger scan. A rejected upload costs you a day; a clear one costs 50 KB.
Questions, answered
- Can I type a target size like 200 KB?
- Not directly. Compress PDF offers three levels and shows the new size before you save, so you pick the level that lands under the limit. For a hard limit, start with Max and check the result.
- Will compressing make the text blurry?
- Real text in a PDF is never touched, only the pictures. A scanned page is one big picture, so it does lose some sharpness at Max; check a seal or a signature before you upload.
- Is my mark sheet or certificate uploaded anywhere?
- No. The whole job runs inside your browser tab. The file never leaves your phone or computer, and there is no copy on a server to delete afterwards.
- Does it work on a phone?
- Yes, in Chrome or Safari on Android and iPhone. Larger files take longer on a phone because the work happens on the device.