Compress PDF
Shrink PDF files for email and upload limits.
Balances file size and quality. Good for email and most uploads.
Runs in your browser. Your files never leave your device.
- Three compression levels
- Batch compress with ZIP download
- Nothing uploaded
How to compress a PDF
- Drop your PDF files here.
- Pick a compression level.
- Download the smaller PDFs.
What the three levels actually do
Every level works the same way: it finds the photos embedded in your PDF, shrinks their pixel size if needed, and re-saves them as JPEG at a lower quality. A stronger level allows a smaller maximum image size and a lower JPEG quality.
| Level | Max image size | JPEG quality | Best for |
|---|---|---|---|
| Light | 2200 px on the long side | 85% | Printing, keeping images sharp |
| Recommended | 1600 px on the long side | 75% | Email and most uploads |
| Strong | 1100 px on the long side | 60% | The smallest possible file |
Strong has one more trick: if a PDF looks scanned, meaning its first few pages have no selectable text at all, it renders each full page fresh as a single JPEG at 100 DPI instead of trying to re-encode an embedded image that often will not shrink much on its own.
Why some PDFs barely shrink
- Images that already have transparency, like a logo with a see-through background, are left alone rather than risk breaking the look.
- Images using CMYK, indexed color or an embedded color profile are skipped, since they cannot be safely converted to a smaller JPEG this way.
- Black and white scans compressed with fax-style formats such as JBIG2 or CCITT are skipped for the same reason.
- Small images, under roughly 200 by 200 pixels, are not worth re-encoding and are left as they are.
- PDFs made almost entirely of vector graphics, shapes and text have few or no embedded photos to shrink in the first place.
Picking a level for your situation
Most email providers cap attachments around 20 to 25 MB, and many upload forms are stricter still, often 10 MB or less. Start with Recommended for everyday sharing. Switch to Strong when a file still will not fit, especially for scanned documents, where it makes the biggest difference. Save Light for files you plan to print, where keeping images closer to full resolution matters more than shaving off every extra megabyte.
Compress PDF FAQ
How much smaller will my PDF get?
PDFs full of photos or scans often shrink by 50 to 90 percent. A PDF that is mostly text may barely change, since there are few images to re-encode.
What is the difference between the levels?
Light keeps images close to full size and quality. Recommended balances size and quality for most uses. Strong compresses hardest and, for scanned pages with no selectable text, turns each page into a single smaller image.
Does Strong make my text unselectable?
Only for pages that already had no selectable text, meaning they were scanned images to begin with. Pages with real text keep that text after compressing.
Will this ever make my file bigger?
No. If compressing does not save space, you get the original file back unchanged.
Can I compress several PDFs at once?
Yes. Drop in as many as you like and download them individually or as one ZIP.
Why did my PDF barely shrink at all?
This tool only re-encodes embedded photos as smaller JPEGs. It skips images with transparency, unusual color spaces like CMYK or indexed color, and fax-style black and white scans, since those cannot be safely shrunk the same way. A PDF built mostly from vector graphics or already-compressed images will not change much.
Does compressing touch fonts, links or bookmarks?
No. Only the embedded images are re-encoded. Text, fonts, links and bookmarks stay exactly as they were, except on scanned pages that Strong turns into a single image.
What happens to a scanned PDF at each level?
Light and Recommended try to re-encode any embedded images on the page but often cannot shrink a full-page scan much, since it is usually one large image with an unsupported format. Strong instead renders the whole page fresh as one compressed JPEG, which is why it does the most for scans.