Compress PDF
Shrink PDFs with photos or scans by re-compressing their images. Text stays sharp.
Drop PDF files here
or select to choose from your device
Files are processed on this device. Nothing is uploaded.
How to use Compress PDF
- Add one or more PDFs.
- Choose the compression level.
- Select Compress PDF, check how much each file shrank, and download.
How it works
Most large PDFs are large because of photos and scanned pages stored as JPEG images. This tool finds those images, downsizes oversized ones (to at most 2,000, 1,600 or 1,100 pixels on the long side for light, recommended and strong) and re-encodes them at a lower JPEG quality, in your browser. Text, fonts and vector drawings are not touched, so text stays sharp and selectable.
Results are honest: some PDFs cannot shrink much, for example documents that are mostly text, already optimised, or whose images use formats the browser cannot re-encode safely (CMYK, JPEG 2000, black-and-white fax images). The tool reports exactly how many images it changed and keeps the original if compression would not help.
Frequently asked questions
How much smaller will my PDF get?
Scanned and photo-heavy PDFs often shrink by 50–90%. Text-only PDFs usually shrink very little, and the tool tells you so.
Will text become blurry?
No. Only embedded photos and scans are re-compressed. Text and vector graphics stay exactly as they are.
Is it safe for confidential documents?
Yes. Compression happens in your browser and nothing is uploaded.
Why didn’t a scanned PDF get smaller?
Some scanners save black-and-white pages with special compression (CCITT or JBIG2) that is already very small, or use CMYK or JPEG 2000 images, which are left untouched to avoid colour errors.
Limitations
- Only JPEG images in RGB or greyscale are re-compressed; CMYK, JPEG 2000, JBIG2 and CCITT images are left as they are.
- Fonts are not subset or removed.
- Password-protected PDFs are refused with an explanation; remove the protection first.
Last reviewed November 9, 2026. How we build and test tools.