Compress PDF for Email Attachments
Gmail has a 25MB attachment limit, Outlook 20MB, and many corporate email servers reject anything over 10MB. Scanned PDFs are the most common culprit — a 10-page scan can easily be 20–40MB. Our PDF Compressor reduces file size by compressing embedded images using pdf-lib running in your browser. Your documents never leave your device.
Email Attachment Limits by Provider
- Gmail: 25MB per email
- Outlook/Hotmail: 20MB per email
- Yahoo Mail: 25MB per email
- iCloud Mail: 20MB per email
- Corporate email servers: Often 10MB or less
Even when your email provider allows 20-25MB, many recipients' servers have lower limits. Keeping PDFs under 10MB ensures reliable delivery.
Why Scanned PDFs Are So Large (And How to Fix It)
When you scan a document, each page is stored as a JPEG image inside the PDF. A typical letter-size scan at 300 DPI creates a 2-3MB image per page. A 10-page scan becomes 20-30MB instantly.
PDF compression works by reducing the quality of these embedded JPEG images. At moderate compression levels, the text remains perfectly readable while file size drops by 50-80%. Text-only PDFs (like those exported from Word) are already optimized and won't compress much further.
Frequently Asked Questions
How much can I reduce a PDF?
Scanned PDFs can be reduced by 50-80%. Text-only PDFs have very little room for compression as they're already optimized.
Will compression reduce quality?
Embedded images may be slightly affected at high compression levels, but text and vectors remain unaffected and fully readable.
Is my PDF uploaded?
No, all compression is done in your browser using pdf-lib. Your documents never leave your device.
What if it's still too large?
Try deleting unused pages first, or consider sharing via a cloud link instead of email attachment.