How to compress a PDF
- Select the PDF you want to make smaller.
- Pick a compression level. Recommended is a good balance of size and readability.
- Click Compress PDF and wait while each page is processed.
- Check the before and after size, then click Download.
How the compression works
PDFs get big mainly because of images: scanned pages, photos and screenshots. The three image-based levels open each page, draw it at a lower resolution and save it as a compressed JPEG inside a new PDF.
| Level | Resolution | Best for |
|---|---|---|
| Light | 150 DPI | Documents you may print |
| Recommended | 110 DPI | Email attachments and online forms |
| Strong | 80 DPI | Strict upload limits, on-screen reading only |
| Keep text selectable | Unchanged | Typed documents where search and copy matter |
The trade-off is honest and simple: the image levels give big savings, but the text becomes part of a picture, so it can no longer be selected, searched or read aloud by screen readers. If that matters, use Keep text selectable. It rebuilds the file’s internal structure without touching the content. Savings are usually modest.
When compression won’t help
A PDF made from a Word document with no images is usually only a few hundred kilobytes and is already efficient. The tool compares the result with your original and tells you when compressing would not make it meaningfully smaller, so you never download a worse file for nothing.
Tips for hitting an upload limit
- Try Recommended first and check that small print is still readable.
- Still too big? Use Strong, or split the PDF and send it in parts.
- For scanned photos, shrinking the images before making the PDF works even better: use Compress Image, then JPG to PDF.
Your document is processed in your browser and never uploaded.
Frequently asked questions
How much smaller will my PDF get?
Scanned documents and PDFs full of photos often shrink by 50 to 90 percent. PDFs that are mostly typed text are usually small already and may not shrink much; the tool tells you if compressing would not help.
Why can't I select the text after compressing?
The image-based levels re-save each page as a compressed picture, which is what produces the large savings. If you need searchable text, choose Keep text selectable, which tidies the file without converting pages to images.
Is my PDF uploaded to a server?
No. The compression runs in your browser, so the document stays on your computer or phone.
What level should I use for an email attachment?
Start with Recommended. If the file is still over the limit (often 20 to 25 MB for email), try Strong, then check the pages are still easy to read.