A PDF that is just a few pages can easily reach 10 MB or more, especially if it was scanned or created from phone photos. Many portals only accept 100 KB to 2 MB. Here is what is going on and how to fix it.
Why PDFs get big
Most of the size is pictures. A scanned page is one large image, and a scan at high resolution can be several megabytes per page. Plain text pages are tiny by comparison.
Option 1: Scan or photograph at a lower resolution
If you are making the PDF yourself, 150 DPI is enough for reading on screen and for most uploads. Scanning at 600 DPI makes files four times bigger for no real benefit.
Option 2: Use a target-size compressor
The easiest route is to tell a tool the size you need. With the PDF compressor, choose 200 KB, 500 KB, 1 MB or your own number. It finds the best quality that fits and tells you when a target is too small to stay readable.
What to expect
To reach small sizes, each page is turned into a compressed picture. It looks the same on screen but the text is no longer selectable. Keep the original file for yourself, and send the small copy to the form.
If it is still too big
- Split the PDF. Upload it in parts using the split PDF tool if the form allows more than one file.
- Use black and white. Colour takes space, and a grey version is often 30-50% smaller.
- Remove unneeded pages. Extract only the pages the form asks for.
- Retake poor scans. Dark, shadowy scans compress badly.
Merging first
If you are sending several documents, merge them first and then compress the combined file once, so you only need one upload.
Your documents are handled inside your browser. They are never uploaded to CometBits.