Compress PDF: Reduce PDF File Size
Shrink a scanned or photo-heavy PDF for email or an upload form. It's compressed on your device, not on a server.
or drop it here
Accepts: PDF
Converted on this device. Your files are never uploaded.
What gets smaller and what doesn't
Most of a large PDF's size is usually images: scanned pages and photos. Compression re-saves each of them as a JPEG at a lower resolution and quality, and also compacts the file's structure by packing objects into compressed object streams and recompressing other streams.
Text and vector graphics, such as lines, tables and charts drawn as shapes, aren't touched, so typed text stays sharp and you can still select and search it. That's also why a PDF that is mostly text gets only a little smaller.
Three levels
Strong scales each image down to about 1240 pixels on its long side at JPEG quality 55. Balanced, the default, uses about 1600 pixels at quality 70, and Light about 2400 pixels at quality 82.
For a scan that fills an A4 page, that works out to roughly 106, 137 and 205 DPI. Start with Balanced; if small print looks soft, try Light, and if the file is still too big, try Strong.
When the result isn't smaller
The page shows the size before and after. If the compressed file wouldn't be smaller, you get the original back with a note, so you never end up with a bigger file.
Images in less common color formats (CMYK, 16-bit, JPEG 2000 or indexed color) are left as they are. A PDF that needs a password to open must be unlocked with Unlock PDF first; PDFs that only restrict copying or printing can be compressed directly.
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Questions
How much smaller will my PDF get?
It depends on what's inside. Scanned documents and PDFs full of photos often shrink a lot. A PDF that is mostly typed text shrinks little, because text is already compact and isn't changed.
Will the text still be sharp and selectable?
Typed text, yes: only images are re-saved, so it stays real text you can select, copy and search. In a scanned document the text is part of the page image, so it can get slightly softer, most noticeably at Strong.
It's still over the limit after Strong. What now?
Split it into parts with Split PDF and send them separately, or ask whether the receiver accepts a link to a cloud file instead of an attachment.
Can I compress a password-protected PDF?
If it asks for a password when you open it, remove the password with Unlock PDF first (you'll need to know it). PDFs that only block copying or printing work as they are.
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