Got a PDF that bounced when you tried to email it? Here's how to shrink it and what quality preset to use.
The 30-second version
- Open Compress PDF.
- Drop the file. Set quality to ebook (the default).
- Click Compress PDF.
- Download the result. Check the new size — most scanned documents shrink 50–90%.
- Send the smaller file.
If you want to check the size BEFORE uploading anything, run the free size check first. It tells you in seconds whether the file will fit in Gmail or Outlook and how much compressing would save.
Which quality preset to use
DocShop offers four quality presets. Pick based on what the recipient will do with the file:
| Preset | DPI | Use when | Typical savings | |---|---|---|---| | Screen | 72 | Recipient will only read on a screen | 80–95% | | ebook | 150 | Recipient may print occasionally | 50–80% | | Printer | 300 | Recipient will print at standard quality | 20–50% | | Prepress | 300+ | Recipient will print professionally | 5–20% |
Default: ebook. 150 DPI is screen-readable and print-acceptable. It's the sweet spot for 90% of use cases.
If the file is a scanned contract that needs to be printed and signed, use printer. If it's a photo-heavy catalog being emailed for review, screen is fine.
Why scanned PDFs shrink the most
A scanned PDF is one full-page image at 300-600 DPI per page. A single scanned page can weigh 5–10 MB. A 20-page scanned contract is easily 100 MB.
When you compress at ebook quality, the images are downsampled to 150 DPI and re-encoded. The text layer (if there is one) is untouched. The result is visually identical at screen size.
If you don't have a text layer (image-only scan), compression won't create one. To make the text searchable and the file much smaller, run OCR first (macOS Preview, Adobe Acrobat, or any free OCR tool), then compress.
What if compressing isn't enough?
If you're still over 25 MB after compressing, the file is probably very long. Two options:
- Split the PDF. Use Split PDF to extract just the pages you need. A 200-page contract where you need pages 14–22 becomes a 9-page PDF.
- Send a link instead. DocShop's share-link feature (Pro) creates a one-time download URL. The recipient clicks and downloads; no attachment limit.
Don't do this
- Don't re-save from a screenshot. Re-printing a PDF as a screenshot of itself adds compression artifacts and often makes the file larger.
- Don't convert to JPG and back. A PDF → JPG → PDF round trip destroys the text layer and usually makes the file larger.
- Don't use an unknown online compressor. Most require an upload and have unclear retention. DocShop runs the conversion on an isolated worker, deletes the upload and result within an hour, and never reads the content.
Privacy
When you compress a PDF on DocShop, the upload and the result are deleted within an hour. The conversion runs in an isolated container. No human access. No training on your data. See How we handle your files for the full timeline.