Compress PDF
Optimize PDF size for email or web upload. Compression preserves text and image quality.
Drag & drop a file here or click to browse
Max size: 25 MB
Why compress a PDF
A heavy PDF won't go through as an email attachment, takes ages to upload, and eats storage. Compression rebuilds the file so it weighs less while the pages still look the same — text stays readable and images keep enough detail. Upload your file and PDF Boss trims the size for you.
How to compress a PDF
- 1Upload your PDF — drag it into the window or pick it from your device.
- 2Wait a moment while the file is analysed and optimised.
- 3Check how much smaller it got — the before and after size is shown.
- 4Download the lighter PDF, ready to email or upload.
When compression helps
Reach for it whenever a PDF is too heavy for where it needs to go:
- •the file won't attach to an email — it's over the size limit;
- •a portal or form rejects the upload as too large;
- •a scanned document came out huge;
- •you're saving storage or sending many files at once;
- •a print or copy shop asks for a lighter version.
What you get when compressing here
Smaller files
Bulky scans and image-heavy PDFs shed most of their weight, often by half or more.
Readable result
Text stays crisp and images stay clear enough to read on screen and in print.
Ready for email
Fit the file under the attachment limit your mail provider sets.
Faster uploads
A lighter PDF goes up to portals, forms and clouds in less time.
One click
No settings to puzzle over — upload and download, the tool handles the rest.
No watermarks
The compressed file comes back clean, with no logos or stamps added.
No sign-up
Compression works straight away, no account needed.
Files don't linger
Your PDF and the result are deleted from the server automatically after an hour.
What actually gets compressed
Most of a PDF's weight sits in scanned pages and embedded photos. Compression re-encodes those images at a sensible resolution and strips redundant data, while text and vector graphics stay sharp because they aren't pixels. A file that's mostly plain text is already small and won't shrink much — the big wins come from image-heavy and scanned PDFs.
Size versus quality
The tool aims for a balance: a clear drop in file size with no obvious loss on screen. Photos may give up a little fine detail you'd only spot zoomed in, but documents stay perfectly legible. If a file is already lean, you'll see only a small change — that just means there was little to trim.