How to Compress a PDF Without Ruining Quality
Upload portals often reject files over 2, 5 or 10 MB. Compression usually fixes that — if you understand what it changes.
By the Easy PDF Tool team at Digimarket Group SIA · Updated 4 November 2026
Why PDFs get large
- Scans and photos: a scanned page is an image. A 600 dpi colour scan can be several megabytes per page.
- Embedded fonts and high-resolution graphics from design software.
- Duplicate or unused objects left after repeated editing.
What compression does
Compression mainly lowers the resolution of images and re-encodes them more efficiently, and removes unused data. Text created digitally (not scanned) stays sharp because it is stored as text, not pixels. Scanned text is an image, so heavy compression can make it blurry.
Steps
- Open the Compress PDF tool.
- Upload the file.
- Run compression and download the result.
- Open it and zoom to 100% on the smallest text. If it is still readable and the size is under the limit, you are done.
Still too big?
- Split off pages the recipient does not need (how to split).
- Rescan at 150–200 dpi in greyscale for text documents; 300 dpi is rarely needed for screen reading.
- For photo-heavy files, resize images before creating the PDF.
- Upload large files as several smaller parts, if the portal allows it.
Typical scan sizes
| Scan setting | Approx. size per A4/Letter page |
|---|---|
| Black & white, 200 dpi | 50–150 KB |
| Greyscale, 200 dpi | 200–600 KB |
| Colour, 300 dpi | 1–3 MB |
Sizes vary with content and scanner, so treat these as rough guides.
Keep a master copy
Compression is usually lossy for images. Keep the original for printing or archiving and send the compressed copy.