PDF tool
Compress a PDF
Reduce PDF file size for free by shrinking the images inside it. See the real before and after size. It runs in your browser and we never upload your file.
Drop a PDF here
Never uploaded · processed in this tab
What this tool does
Compress PDF makes a PDF smaller by shrinking the photos and scanned pages inside it. Each image is re-saved at a lower resolution and quality, images that appear more than once are stored only once, and the file is saved in a more compact form. Text and drawings are not touched, so they stay sharp. You see the real size before and after, never a promised percentage.
How to compress a PDF
- Choose a PDF, or drop it onto the box above.
- Pick Light, Balanced or Strong compression.
- Select Compress PDF and wait while the images are re-saved.
- Check the before and after size, then download the smaller file.
What happens to your file
We never upload your file. Compression runs inside this browser tab, on your own device, which is also why very large files depend on how much memory your device has. Nothing is sent to our servers or stored by us.
What it cannot do
- A PDF that is mostly text barely shrinks: text is already compact. If the result would be no smaller, you get your original back, with a note saying so.
- Some image formats are left as they are to protect their quality: CMYK print images, black-and-white fax-style scans (JBIG2 and CCITT), JPEG 2000 and images with transparency keys.
- It cannot open a password-protected PDF. Remove the password first with Unlock PDF, using the password you already have.
- Images become JPEG, so a sharp-edged graphic can pick up slight blur at Strong.
Frequently asked questions
It depends on what is inside. Scans and photo-heavy documents often shrink a lot, while a PDF that is mostly text may barely change. We show the real size before and after rather than promising a percentage.
Most photos and scanned pages inside the PDF are re-encoded at a lower resolution and quality, duplicate images are stored once, and the file is saved in a more compact structure. Text and vector graphics are not touched.
Then you get your original file back, unchanged, with a note explaining that there was nothing worth shrinking. We never hand you a larger file than the one you started with.
No. We never upload your file. Compression runs in your browser on your own device, which is also why very large files depend on how much memory your device has.