Why Is Your PDF So Large?
Before compressing, it helps to understand why your PDF is big. The most common causes:
- 1.Scanned pages. Each scanned page is stored as a full-page image (often 2-5MB per page). A 10-page scanned document can easily hit 20-50MB.
- 2.High-resolution images. Photos, charts, and graphics embedded at print quality (300 DPI) take up significant space.
- 3.Embedded fonts. PDFs that include custom fonts embed the full font file, adding hundreds of KB per font.
- 4.Layers and annotations. Form fields, comments, and interactive elements add extra data. Flattening your PDF removes these.
How to Compress a PDF (Step by Step)
Upload your PDF
Go to the Compress PDF tool and drag your file into the upload area, or click to browse. Files up to 25MB are free — Pro users can upload up to 200MB.
Choose your compression level
Pick Light (minimal quality loss), Medium (good balance), or Extreme (maximum size reduction). For email attachments, Medium usually works. For strict upload limits (2MB, 5MB), try Extreme.
Download the compressed PDF
Click Compress PDF. Once processing is done, download your smaller file. Check the new size — if it's still too large, try a higher compression level or split the PDF into parts first.
Which Compression Level Should You Use?
| Level | Best For | Quality |
|---|---|---|
| Light | Sharing documents where quality matters (reports, portfolios) | Near-original |
| Medium | Email attachments, general sharing, most upload portals | Good — text stays sharp |
| Extreme | Strict upload limits (1MB, 2MB, 5MB), government portals, visa forms | Reduced — images may lose detail |
PDF Still Too Large After Compression?
If compression alone doesn't get your file small enough, try these approaches:
- ✓ Split the PDF into smaller parts using Split PDF, then compress each part separately.
- ✓ Flatten the PDF first with Flatten PDF to remove form fields and annotations before compressing.
- ✓ Try Extreme compression if you haven't already — it gives the maximum size reduction.
- ✓ Remove unnecessary pages using Remove Pages before compressing.
Compression Tips for Common Scenarios
For Email Attachments
Gmail, Outlook, and Yahoo cap attachments at 20-25MB. Medium compression usually gets PDFs under this limit. For tighter limits, try our Compress for Email tool which is optimized for email services.
For Upload Portals (Government, Visa, Exams)
Many portals require PDFs under 2MB or 5MB. Use Extreme compression, and if the file is still too large, split it into individual pages first. See our dedicated tools for 2MB limits and 5MB limits.
For Scanned Documents
Scanned PDFs compress dramatically because they're mostly images. Extreme compression can reduce a 20MB scanned document to 2-4MB while keeping text readable. See Compress Scanned PDF for more tips.