When you convert images to PDF, you are making a choice. Do you use JPG? PNG? Or the newer WebP? The format you choose for your source images dramatically affects the final size and quality of your PDF document. In this technical deep dive, we compare the big three formats to help you decide.
1. JPG (JPEG) - The All-Rounder
Best for: Photographs, Scans, Real-world scenes.
JPG is a "lossy" format. It saves space by throwing away visual data that the human eye barely notices. This makes it perfect for photos.
- Pros: Smallest file size. widely supported.
- Cons: No transparency. Text can look "fuzzy" (artifacts) if compressed too much.
Verdict: Use JPG for scanned documents or photos where file size is the priority.
2. PNG - The Crisp Professional
Best for: Screenshots, text-heavy images, logos, diagrams.
PNG is "lossless". It preserves every single pixel exactly as it is. This is crucial for text, where even a slight blur makes it unreadable.
- Pros: Crystal clear text. Supports transparency.
- Cons: File sizes can be huge (5x larger than JPG) for complex photos.
Verdict: Use PNG for screenshots of documents or digital art with sharp lines.
3. WebP - The Modern Contender
Best for: Everything (if supported).
Developed by Google, WebP offers the best of both worlds. It supports transparency like PNG but with file sizes comparable to (or smaller than) JPG.
- Pros: Superior compression. Supports transparency.
- Cons: Older software might not open it (though modern browsers and EasyEditPDFs support it fully).
Verdict: If your target is the web, use WebP.
Impact on PDF Size
We ran a test converting 10 images to PDF using our Image to PDF Converter.
| Source Format | Final PDF Size | Quality |
|---|---|---|
| JPG (80%) | 1.2 MB | Good |
| PNG | 8.5 MB | Perfect |
| WebP | 0.9 MB | Great |
Conclusion
For most PDF tasks, JPG is the winner simply because PDFs are often emailed, and size matters. However, if you are creating a PDF portfolio of your digital art or screenshots of a UI design, stick to PNG to keep those lines sharp.