“Simplicity is the ultimate sophistication.”
Compress PDF Online
Shrink large PDFs for email attachment limits or faster uploads, with a choice of compression levels so you control the quality/size tradeoff.
- No sign-up, no watermark
- Files encrypted and auto-deleted
- No installation — runs right in your browser
- Fast processing on desktop and mobile
Read our full guide: How to Reduce PDF File Size for Email (Under the Attachment Limit) →
How to use Compress PDF online
- 1
Upload your files
Drag and drop or click to select your file(s). Uploads go directly to encrypted cloud storage over HTTPS. (PDF)
- 2
Run the tool: Compress PDF
Processing happens instantly in the cloud — no software to install, works on Windows, Mac, Linux, iOS and Android.
- 3
Download the result
Get your processed file via a secure temporary link. All files are deleted automatically about a day after upload.
Frequently asked questions
How much smaller will my PDF get?
It depends on content — image-heavy PDFs (scans, photo reports) often shrink 50-90%; text-only PDFs are already compact and typically save under 10%. Whatever the result, the tool tells you what it did and why, and never returns a file larger than the one you uploaded.
Why didn't my PDF get any smaller?
Some PDFs have nothing left to give, and Compress PDF says which case yours is: a text-and-vector PDF stores instructions rather than pixels and is already compact; a 1-bit black-and-white scan (CCITT/JBIG2) already uses the most efficient encoding for that content, so re-encoding it as JPEG would make it bigger; and a file that's already been compressed has images at or below the quality we'd target. In those cases we hand back your original file unchanged instead of a larger one.
Will compression make text blurry?
No — text and vector graphics stay fully sharp at every compression level; only embedded raster images are recompressed.
What's the difference between the compression levels?
Auto (recommended) inspects the PDF — how much of it is image data, whether it looks like a scan — and picks the setting that suits it. Good keeps images near-original quality with modest savings; Better balances size and quality; Smallest applies the most aggressive image recompression for the smallest possible file.
Can I compress a password-protected PDF?
Not directly — an encrypted PDF's structure has to be preserved as-is, so run Unlock PDF on it first and then compress the unlocked file. Compress PDF tells you this instead of failing with a generic error.
Can I compress a PDF to a specific target size, like 100KB?
Not to an exact byte target — pick the compression level that gets you closest, since final size depends on the source content, then re-run at a higher level if it's still too large.