Getting a PDF under 50 MB
Uploads can be up to 50 MB. A file over that is almost always a print file: its photos carry far more detail than a screen can show.
Why you can shrink it without losing anything
Section titled “Why you can shrink it without losing anything”We turn every page into an image sized for screens: for an A4 page, about 900 pixels wide, roughly 108 pixels for every inch of page. That’s what your readers see.
A PDF exported for print holds its photos at 300 pixels per inch, nearly three times the width and height we render at, so most of that detail never reaches a reader. Bring images down to around 150 ppi and the page looks the same in Living Page, with room to spare, while each photo carries about a quarter of the data.
Only images shrink. Real text and vector graphics stay sharp whatever you choose.
Best: re-export from the original
Section titled “Best: re-export from the original”This always beats compressing a finished PDF, because the app still has the full-quality images and can resize them properly.
| App | What to change |
|---|---|
| PowerPoint | Windows: Optimize for → Minimum size. Or compress pictures first: Picture Format → Compress Pictures at 150 ppi |
| Word | Picture Format → Compress Pictures, all pictures, 150 ppi (Word’s default is 220) |
| Canva | The Digital (PDF Standard) preset, not Print |
| InDesign | Interactive PDF at 144 ppi, or the Smallest File Size print preset |
| Affinity | Downsample images above 150 DPI, or the PDF (digital - small size) preset |
| Keynote and Pages | A lower Image Quality when exporting |
| Google Docs and Slides | No export setting. Replace very large images in the doc with smaller copies |
If you only have the PDF
Section titled “If you only have the PDF”- Adobe Acrobat: Save as Other → Reduced size PDF, or Optimized PDF for control over image resolution. See Adobe Acrobat.
- Preview on a Mac: File → Export, and choose a Quartz Filter that reduces file size. Check the result: it can soften photos a lot.
- Online compressors work too, but you’re uploading the file to someone else’s server. Avoid them for anything confidential.
Other things that make a file big
Section titled “Other things that make a file big”- Scans. Every page is a photo. A lower quality setting in your scanning app shrinks the file, but keep text crisp: text recognition (OCR) reads a sharp scan far better than a soft one. See Scanned documents.
- Crop marks and bleed add little size but belong to the print version. Leave them off.
- CMYK images. Print presets often keep images in CMYK, the printer’s four-ink model, which stores more data per pixel than the RGB a screen uses. Screen presets convert to RGB.
Check you haven’t gone too far
Section titled “Check you haven’t gone too far”Open the smaller PDF and zoom to the size people will read it. Look at the photos, not the text: if skies look blocky or product details look soft, go back one step, to a higher quality or 200 ppi.