How it works
How to compress a PDF
- Choose your PDF. Scanned documents and image-heavy PDFs shrink the most.
- Pick a compression level. Recommended works for most uploads; Strong for strict size limits; Light when quality matters most.
- Optionally switch to grayscale for black-and-white documents — it often saves even more.
- Click Compress PDF and download. You'll see the old size, new size and savings.
Real test results (measured)
How this compressor works — and its trade-off
Each page is redrawn as an optimized image at a lower resolution and rebuilt into a new PDF. This shrinks scanned documents and photo-heavy PDFs dramatically.
Trade-off: because pages become images, text in the compressed copy is no longer selectable or searchable, and links stop working. That's usually fine for uploading scans, IDs, certificates and forms — but keep your original if you need to copy text later.
| Level | Resolution | Best for |
|---|---|---|
| Strong | 72 DPI | Strict upload limits, on-screen viewing |
| Recommended | 110 DPI | Most forms and email attachments |
| Light | 150 DPI | Documents you may print |
Text-only PDFs exported from Word or Google Docs are usually already small. If compressing makes a file larger, the tool tells you to keep the original.
Frequently asked questions
How can I reduce PDF size for an upload limit?
Choose your PDF, select Recommended (or Strong for strict limits), and click Compress PDF. Scanned and photo-heavy PDFs typically shrink by well over half.
Will compression make my text blurry?
At Recommended and Light, text stays easy to read on screen. Strong is smaller but softer. Text also becomes part of the page image, so it can't be selected afterward.
Why did my PDF get bigger?
PDFs made from text documents are already efficient. Converting their pages to images can increase the size — the tool warns you and you can keep the original.
Can I compress password-protected PDFs?
No. Remove the password first, then compress the unlocked copy.
Are my files uploaded to a server?
No. Everything happens in your browser on your own device. Your files are never sent to or stored on our servers.
Does it work on my phone?
Yes. It works in modern browsers on iPhone and Android. Very large files may be slow on older phones.