How to shrink a scanned PDF
A one-page letter exported from Word is 50 KB. The same letter as a scan can be 5 MB — a hundred times larger — because a scan is a photograph of the page, not text. The good news: that also means scans compress dramatically well.
Drag and drop here, or choose from your device.
Up to 50 MB per file. Files are processed in your browser.
Full options and FAQs on the Compress PDF page.
Why scans balloon
- Each page is a full-resolution image, often 300 DPI in colour even for black-and-white documents.
- Flatbed and feeder scanners default to quality settings designed for photographs, not paperwork.
- Some scanning apps add an invisible OCR text layer on top of the image, adding more weight.
How much you can expect to save
Scans are the best-case scenario for compression: 70-90% reductions are routine at the medium level, because most of the image detail is paper texture and shadow that nobody needs. A 50 MB scan commonly lands under 10 MB with text still perfectly readable.
What does not shrink well is a scan of photographs or colour graphics, where the detail is the content. Judge those by eye after compressing.
Prevent the problem at the source
If you scan regularly, set the scanner to 200 DPI greyscale for paperwork — the files come out a fraction of the size before you compress anything, and nobody can tell the difference for a contract or a receipt. Keep 300 DPI colour for certificates and anything with stamps or seals.
Step by step
- 1Add the scanned PDF to the compressor below.
- 2Choose medium — it is designed for exactly this kind of file.
- 3Check the new size; step up to strong if you are still over a limit.
- 4Zoom into the finest print and the signature area to confirm legibility.
- 5Download and send the smaller file.
Frequently asked questions
- Will the scan still be accepted officially?
- Yes, provided the text, stamps and signatures remain legible — which the medium level preserves. Check the result at full zoom before submitting anything official.
- Does compression remove the searchable text?
- Image-based compression rasterises pages, so an OCR text layer is lost. Run the OCR tool again on the compressed file if you need searchability back.