How to Compress PDF Files on MacSave 50-80% storage space without losing quality
What Is PDF (Portable Document Format)?
PDF is the universal document format created by Adobe, used for contracts, reports, manuals, books, and scanned documents. PDFs can contain text, images, vector graphics, forms, and embedded fonts. It is the standard for document sharing across all platforms and industries.
Why Are PDF Files So Large?
PDF files become large when they contain high-resolution scanned pages (300-600 DPI images), embedded fonts (each font can add 100-500KB), uncompressed images, or redundant data from editing. Scanned PDF documents are essentially collections of images, making them especially bloated.
Typical PDF Compression Results
Before
1-50MB per document
After
200KB - 10MB per document
50-80%
Smaller
Compression Ratio
2:1 to 5:1
Codecs
JPEG, JPEG2000, CCITT, Flate/Deflate for internal images
How to Compress PDF Files on Mac (Step by Step)
Follow these steps to compress your PDF files using MediaOptim on macOS:
Open MediaOptim
Launch MediaOptim. It has dedicated PDF compression with smart image handling.
Add PDF files
Drag your PDF documents into the app. MediaOptim analyzes the composition of each PDF (text, images, fonts).
Choose quality level
Select "Screen" for smallest size, "Balanced" for good quality and size, or "Print" to maintain 300 DPI images.
Compress
MediaOptim compresses internal images, subsets fonts, and removes unnecessary metadata.
Save
Review the compressed PDF. Text remains sharp at any zoom level. Only embedded images are affected by compression.
PDF Technical Details & Compression Tips
Best Quality Settings
For screen viewing: compress images to 150 DPI. For printing: keep 300 DPI. Remove duplicate fonts and flatten forms. Linearize for faster web loading.
When to Convert vs Compress
Keep PDF format, but optimize it. PDF is already the universal document standard. Focus on compressing internal images and removing unnecessary data rather than converting to another format.
Technical Specifications
- Container format with text, images, vector graphics, and fonts
- Scanned PDFs are essentially image collections (largest PDFs)
- Image resolution: 72 DPI (screen), 150 DPI (balanced), 300 DPI (print)
- Font subsetting removes unused characters, saving 50-90% per font
- Linearization enables progressive loading (first page loads immediately)
Frequently Asked Questions
How do I compress PDF files on Mac?
Use MediaOptim to compress PDF internal images, subset fonts, and remove unnecessary data. Typical savings are 50-80%, especially for scanned PDFs.
Will compressing a PDF affect text quality?
No. PDF text is vector-based and remains sharp at any zoom level after compression. Only embedded raster images are compressed.
How do I reduce scanned PDF file size?
Scanned PDFs are image-heavy and benefit most from compression. Reducing image resolution from 600 DPI to 150-200 DPI can save 75-90% with acceptable quality for screen viewing.
Can I compress password-protected PDFs?
MediaOptim can compress PDFs that you have the password for. Enter the password when prompted, and the compressed output will maintain the same protection.
What is the best PDF size for email attachments?
Most email services limit attachments to 25MB. Use MediaOptim's "Screen" or "Balanced" compression to reduce PDFs below this limit while maintaining readability.
Compress Your PDF Files Now
Save 50-80% on your PDF files. No quality loss. Everything stays on your Mac.
Try MediaOptim Free10 files free. No credit card. No signup.