How to Reduce PDF File Size for Email

Most email services enforce a maximum attachment size, usually between 10 and 25 MB. When a PDF exceeds that limit — especially if it holds high-resolution images or scanned pages — you get an error blocking the send. The fix isn't necessarily splitting the file or uploading it to a cloud service, but compressing it to make it lighter.

PDF compression mainly targets embedded images, redundant data, and duplicated fonts inside the file. Text stays sharp and clear because it's lightweight vector data to begin with, while images consume most of the size. That's why image-heavy or scanned files can shrink to less than half their size, while pure-text documents drop less because they're small from the start.

To compress your file, open the Compress PDF tool, upload the document, and click the compress button. Within seconds you'll get a smaller copy ready to send. And if your file is made of several parts you merged earlier, compressing after merging gives a better result than compressing each part separately.

If the file stays large after compression — like a huge scanned book of hundreds of pages — consider splitting it into parts with the Split PDF tool and sending them in successive emails. But if the size is close to the limit, compression alone is usually enough.