Compress PDF
Shrink PDF file size while keeping pages readable.
- 100% Private
- No Limits
- Works Offline
or drag and drop here
Reduce a PDF's file size by re-encoding the photos inside it at a lower quality — the images are usually what makes a PDF large, not the text. Everything runs in your browser, so the file you're shrinking never leaves your device.
How to Use Compress PDF
- 1
Upload your PDF
Click the upload area or drag in the file you want to shrink.
- 2
Pick a compression level
Low keeps the most quality, High gives the smallest file — Recommended is a good default.
- 3
Compress and download
See the before/after size right away, then download the smaller file — nothing is uploaded first.
Why Choose PurePDF for Compress PDF
Nothing leaves your device
Images are re-encoded locally via your browser's canvas — never sent to a server.
See the size drop before downloading
The before/after file size is shown immediately after compressing.
Choose your own tradeoff
Three levels let you pick quality vs. file size instead of a one-size-fits-all result.
Common Use Cases for Compress PDF
Fit an email attachment limit
Shrink a scanned document or photo-heavy PDF below a size cap.
Faster uploads
Smaller files upload faster to any site or form that accepts PDFs.
Save storage space
Compress a large archive of scanned PDFs before backing them up.
Pro Tips for Compress PDF
- A text-only PDF (no photos or scans) won't shrink much — there's little image data to compress.
- Try Recommended first; only go to High compression if the file still needs to be smaller.
- Compressing an already-compressed PDF twice rarely helps — start from the original if you can.
Frequently Asked Questions About Compress PDF
Will my PDF file be uploaded to a server?
No — nothing is uploaded. This tool runs entirely in your browser via WebAssembly/JavaScript; your file never leaves your device.
Is there a file-size limit, a usage cap, or a hidden fee?
It's free and unlimited, with no watermark and no forced file-size cap — the only real limit is your own device's memory for very large files.
Do I need to create an account or sign up?
No — no account, email, or sign-up is required for any tool. Just start using it.
Can I use this on my phone (iPhone or Android)?
Yes — it works in any modern mobile browser, no app install needed.
Why does compressing a text-only PDF result in little size reduction?
A text-only PDF with no photos or scans won't shrink much because there is little image data to compress.
Can I compress the same PDF multiple times to make it even smaller?
Compressing an already-compressed PDF twice rarely helps; always start from the original file if you need more compression.