How to Shrink a PDF for Email — Under Any Attachment Limit
Updated July 20, 2026
"Attachment too large" is one of email's most stubborn errors: most providers cap attachments at 10–25 MB, and a scanned contract blows past that easily. Here is how to get any PDF under the limit — without uploading it to a compression website.
1. Know why your PDF is huge
Text-based PDFs (exported from Word, invoices, tickets) are almost always small. The heavyweights are scans and photo-rich documents: every page is stored as a full-resolution image, which easily means 1–2 MB per page. That's the lever compression pulls.
2. Compress the PDF
Open PDF Compress and drop in your file. The tool re-encodes the page images at a sensible quality — scans typically shrink by 60–90% while staying perfectly readable. A 40 MB scanned contract usually lands well under 10 MB.
The compression runs locally in your browser, which matters here specifically: the PDFs people need to email — contracts, payslips, medical records — are exactly the ones that shouldn't pass through a stranger's server.
3. Still too big? Split it
For very long documents, compression alone may not be enough. PDF Split extracts page ranges into separate files — send a 120-page report as two or three parts, or extract just the pages the recipient actually needs.
4. Sending many files? Merge first
The reverse problem — ten small PDFs cluttering one email — is solved with PDF Merge: combine them into a single document, in the order you choose, then compress the result if needed.
Quick reference: attachment limits
Gmail and Yahoo allow 25 MB, Outlook.com 20 MB, most corporate mail servers 10 MB — and the limit applies to the encoded message, which is about a third larger than the file itself. Aim for 7 MB on corporate mail and 15 MB elsewhere and your attachment will always go through.