How to make a PDF small enough to email
Guides · Updated 12 October 2026 · By Tiago Santos
You attach a PDF, press send, and the email bounces or your mail app offers a cloud link instead. Most email services cap attachments at 20 to 25 MB per message, and the receiving server may accept even less.
Typical attachment limits
- Gmail: 25 MB per email. Larger files are sent as a Google Drive link.
- Outlook.com and Microsoft 365: about 20 MB by default (organisations can change this).
- Yahoo Mail and iCloud Mail: 25 MB. iCloud can send larger files with Mail Drop.
Attachments grow by about a third when they’re sent, because of how email encodes files. So aim for well under the limit: a 19 MB PDF can fail a 25 MB limit.
Why some PDFs are so big
Text is tiny. What makes a PDF heavy is pictures: scanned pages, phone photos of documents, and high-resolution images. A 10-page scan at 600 DPI can easily pass 50 MB, while the same pages as text would be a few hundred kilobytes.
Shrink it without losing readable text
Compress PDF has two modes:
- Balanced recompresses only the pictures inside the PDF. Text stays sharp, selectable and searchable. This is the one to try first.
- Strong turns every page into a compressed image. It makes even stubborn scans small, but text can no longer be selected; use it for documents you only need to read.
Scans and photo-heavy PDFs often shrink by 50 to 90%. The PDF is compressed in your browser and never uploaded, which matters for the kind of documents people email: contracts, IDs and payslips.
If it’s still too big
- Remove pages nobody needs with Remove PDF pages, such as blank pages or long appendices.
- Send it in two emails: Split PDF cuts it into parts by page range.
- Next time you scan, choose 200 to 300 DPI and grayscale for text documents. That alone often makes files ten times smaller.