Your PDF is 28MB. You need to email it — your client's server rejects anything over 10MB. The culprit is almost always the images embedded inside. Here's how to compress those images without making your PDF look like a fax from 1995.
When you create a PDF from Word, PowerPoint, or a scanner, the software typically embeds images at their original resolution — often 300 DPI or higher. A single 300 DPI photo can be 5-15MB inside a PDF. Multiply that by a 50-page proposal with product photos on every page, and you have a 200MB monster.
PDFs destined for screens (email, web download, Slack) only need images at 150 DPI. PDFs for print need 300 DPI. Most PDF bloat comes from using print-quality images for screen-only documents.
This applies aggressive compression. Typical result: 28MB → 3-5MB. The quality drop is noticeable if the PDF contains detailed diagrams or small text, so check the result before sending.
For maximum control, extract the images, compress them individually, and rebuild the PDF:
This takes more time but gives you pixel-level control over the quality/size tradeoff.
Prevention is better than cure. Compress your images before inserting them into the document:
This approach produces the smallest possible PDF with no quality surprises.
Tools like Smallpdf and iLovePDF specialize in PDF compression. They're convenient but come with a major caveat: you're uploading your document to someone else's server. For contracts, financial documents, or anything confidential, this is a non-starter. Use offline methods for sensitive PDFs.
| PDF Type | Original Size | After Compression | Reduction |
|---|---|---|---|
| Product catalog (photos) | 32 MB | 4.8 MB | 85% |
| Scanned document | 18 MB | 2.1 MB | 88% |
| Presentation with screenshots | 12 MB | 1.6 MB | 87% |
| Proposal with charts & photos | 8 MB | 1.2 MB | 85% |
All results at 150 DPI JPG 80% quality — perfectly acceptable for screen viewing.