Compress PDF
Reduce PDF file size in your browser with adjustable compression settings.
What actually makes a PDF large?
In most cases, it's the images inside the PDF — high-resolution scans, embedded photos, or screenshots — rather than the text itself. Compression works by re-rendering those pages at a more efficient quality and resolution, which is why a heavily scanned document shrinks the most.
How to compress a PDF
1. Upload your file
Drag and drop the PDF into the tool. Processing happens locally in your browser.
2. Choose a compression level
Pick between smaller file size and higher visual quality, depending on what the PDF is for. A contract someone needs to read closely deserves a higher setting; a quick reference document can go smaller.
3. Let it process
Each page is rebuilt at the chosen quality. Larger, image-heavy documents take a little longer.
4. Compare the result
Check the new file size against the original, and confirm the rebuilt file is still smaller before downloading — if it isn't, try a smaller-file setting.
5. Download the compressed PDF
Save the compressed file and use it wherever the original was too large.
When compression helps most
- Scanned documents with lots of photo-quality pages.
- PDFs built from high-resolution image exports rather than native text.
- Files that need to go through an email attachment limit or upload cap.
If you're specifically trying to get under an email size limit, see our guide to reducing PDF size for email.
Reduce PDF size for sharing
Large PDFs are often caused by scanned pages, embedded photographs or screenshots rather than ordinary text. Compressing a document can make email attachments, uploads and cloud storage easier to manage while keeping the PDF usable for everyday reading.
Choose compression based on the destination
For email and online forms, a smaller file can be more useful than maximum image quality. For printing or close inspection, keep more detail and verify the result after compression. Always compare important pages before replacing the original.
If the PDF is still too large, consider exporting selected pages with Split PDF or converting individual pages with PDF to JPG.
Frequently asked questions
Will compressing a PDF reduce quality?
It can. Moderate compression usually offers a useful balance, while aggressive settings may reduce image detail.
Why are scanned PDFs often large?
Scanned pages are stored as images, which can consume much more space than text-based PDFs.
Can I compare the result with the original?
Yes. Check the resulting file size and review important pages before sharing.