Compress PDF — Reduce PDF File Size Online Free

Reduce PDF File Size Instantly

PDF files too large to email or upload? MyPDF's PDF Compressor reduces file size by up to 90% while maintaining readable quality. Perfect for email attachments, web uploads, and storage optimization.

How to Compress a PDF

Step 1: Upload Your PDF

Go to the Compress PDF tool and upload the PDF you want to shrink.

Step 2: Choose Compression Level

Select your preferred compression level:

• Low compression — Minimal size reduction, best quality (ideal for print)


• Medium compression — Good balance of size and quality (recommended)


• High compression — Maximum size reduction (best for email/web)

Step 3: Download the Compressed File

Your compressed PDF is ready to download. Check the file size comparison to see how much space you saved.

How Much Can You Compress?

Original Size	After Compression	Reduction
50 MB	5–15 MB	70–90%
10 MB	1–4 MB	60–90%
5 MB	500 KB–2 MB	60–90%
1 MB	100–500 KB	50–90%

Results depend on the PDF content. Image-heavy PDFs compress more than text-only documents.

Why PDFs Become Large

• High-resolution images — Photos embedded at print quality (300+ DPI)
• Embedded fonts — Multiple font families increase file size
• Vector graphics — Complex illustrations and diagrams
• Multiple pages — Each page adds overhead
• Metadata — Hidden layers, comments, and revision history

Tips for Maximum Compression

1. Start with high compression — Check if quality is acceptable; if not, try medium
2. Compress after merging — Combined PDFs benefit most from compression
3. Remove unnecessary pages first — Use Split PDF to remove pages you don't need
4. Convert images to grayscale — Use Grayscale PDF before compressing for even smaller files
5. Strip metadata — Removes hidden data that adds to file size

Common Reasons to Compress PDFs

• Email attachments — Most email providers limit attachments to 25MB
• Web uploads — Faster upload speeds, lower bandwidth usage
• Cloud storage — Save storage space on Google Drive, Dropbox, etc.
• Website downloads — Faster downloads for your visitors
• Mobile viewing — Smaller files load faster on phones

Frequently Asked Questions

Does compression reduce quality?

At low and medium levels, quality loss is imperceptible for most documents. High compression may slightly reduce image sharpness, but text remains crisp.

Is there a file size limit?

You can upload PDFs up to 50MB per file. For larger files, try splitting them first with Split PDF.

Can I compress multiple PDFs at once?

Upload multiple files to compress them in batch. Each file is compressed independently.

Will compressed PDFs still be printable?

Yes. Even highly compressed PDFs maintain print-quality text. For best print results, use low or medium compression.

Is it really free?

Yes — no sign-up, no watermarks, no limits. MyPDF's compressor is 100% free.

Related Tools

• Merge PDF — Combine files, then compress the result
• Split PDF — Remove unnecessary pages to reduce size
• PDF to Images — Convert pages to compressed images
• Compress Image — Shrink images before adding to PDFs
• Flatten PDF — Remove interactive elements to save space