Compress PDF Online — Reduce File Size Easily (Free & Secure)
Compress a PDF online for free — PDF compress online with no software to install. Reduce the file size while keeping it readable. Fast, simple and secure.
What Is This Tool?
Compress PDF shrinks the size of a PDF document by re-encoding the images it contains, so it's faster to upload, download, email, and store. It works especially well on image-heavy PDFs like scanned documents, brochures, and photo-filled reports.
Everything runs on our servers over a secure connection; your files are processed, made available for download, and then automatically deleted a short time later.
Why Compress a PDF File?
Large PDFs are slow to upload, awkward to email, and eat up storage space. Compressing reduces the file size — often dramatically for image-heavy documents — while keeping the document readable and usable.
Benefits of Compressing PDFs
- Faster uploads and downloads
- Fits within email attachment size limits
- Saves storage space
- Choice of compression level to balance size and quality
Who Can Use a PDF Compressor?
- Anyone emailing a PDF that's too large to attach
- Businesses archiving scanned documents
- Students submitting assignments with strict upload limits
- Photographers and designers sharing photo-heavy PDFs
- Website owners preparing PDFs for faster page loads
A Few Real-World Examples
- A job seeker can shrink a portfolio PDF full of high-res images so it fits under an application portal's upload limit.
- An office assistant can compress a 40 MB scanned contract down to a size that emails without bouncing.
- A real estate agent can compress a listing brochure full of property photos before uploading it to a slow MLS system.
- A student can compress a scanned assignment so it meets a university portal's strict file-size cap.
- A small business owner can compress years of scanned invoices before archiving them to save on cloud storage costs.
Step-by-Step Guide
Upload the PDF you want to compress.
Choose a compression level.
Click "Compress PDF".
Download your smaller PDF.
Choosing a Compression Level
Low Compression — keeps images closest to their original quality, with a smaller reduction in file size. Best when visual fidelity matters most.
Recommended — a balanced setting that noticeably shrinks most PDFs while keeping images and text easily readable. This is the right choice for most documents.
Extreme Compression — produces the smallest possible file by reducing image quality more aggressively. Best when file size matters more than image sharpness.
What You'll Get
The output is a new PDF with the same pages and text, but smaller, re-encoded images. Your original file is never changed — compression always reads it, never edits it, and you'll see the exact before-and-after file size.
Features
- Free
- Easy to use
- No registration
- Three compression levels to choose from
- Secure processing — files are deleted automatically
Supported Formats
Best Practices
- Start with "Recommended" and only go to "Extreme" if the file is still too large.
- Compress a copy, not your only copy of an important document.
- Text-heavy PDFs will shrink less than image-heavy scans — that's expected.
- If you need the highest quality, use "Low Compression" even if the file size reduction is smaller.
Troubleshooting
Problem: The compressed file barely got smaller
Solution: Compression mainly targets images. A PDF that's mostly text has little to compress, so a small size reduction is normal and expected in that case.
Problem: Images look noticeably blurrier after compressing
Solution: Try a lower compression level — "Low" preserves image quality much more closely than "Extreme," at the cost of a smaller size reduction.
Problem: The file won't upload
Solution: Ensure your file is under 50 MB and is a valid PDF. Try a different browser or a stable network connection for large scanned files.
Choosing the Right Compression Level
| Level | Size reduction | Image quality |
|---|---|---|
| Low Compression | Smallest reduction | Closest to original |
| Recommended | Balanced, noticeable reduction | Good, easily readable |
| Extreme Compression | Largest reduction | Lower, visible softness |
Compress PDF FAQ
Is compressing PDFs really free?
Yes. Compress PDF is completely free, with no sign-up, watermark, or hidden limits beyond the file size shown above.
Is this the same as a PDF optimizer?
Yes — "PDF compressor" and "PDF optimizer" describe the same job: shrinking a PDF's file size. This tool optimizes a PDF online for free by re-encoding its embedded images at a lower resolution and quality, without touching the underlying text.
How much can I expect to save?
It depends on the file. PDFs full of high-resolution images can shrink dramatically, while text-only PDFs may see little change since there are few images to recompress. We always show you the exact before-and-after size.
Will the quality visibly degrade?
Low compression keeps images close to their original quality. Recommended and Extreme trade off some image sharpness for a smaller file — Extreme is more noticeable, so use it when file size matters more than image fidelity.
Will my file be kept after compressing?
No. Both your uploaded file and the compressed result are automatically deleted from our servers a short time after processing.
Does this work on mobile?
Yes, Compress PDF works in any modern mobile or desktop browser — no app required.
Can I compress large PDF files?
Yes, up to the maximum file size shown above — larger files simply take a little longer to process.
Is registration required?
No. You can compress PDFs without creating an account or providing any personal details.
Privacy & Security
Your files are handled securely
All uploads are transferred over an encrypted SSL/TLS connection and processed in an isolated job folder. No one at PDFCherry views, shares, or uses the content of your documents for anything other than completing the compression you requested.
- Uploaded files are automatically deleted within 30 minutes.
- Compressed results are automatically deleted within 1 hour after completion.
- Your original file is never modified — compression always produces a new, separate output file; the PDF you uploaded is read, not altered.
Read our full Privacy Policy or Contact Us if you have any questions about how your files are handled.
Why Trust PDFCherry?
PDFCherry is built and maintained by a small, dedicated team and runs on established, industry-standard PDF libraries — not an anonymous "free tool" that resells your files or data. The privacy practices above apply across the whole site. More about PDFCherry.
Having issues or need help? Contact Us — we're here to help.
Ready to Compress Your PDF?
It's free, secure, and takes just a few seconds. Upload your file and reduce the size now!
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