How to Reduce PDF File Size for Email (Under the Attachment Limit)
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Why your PDF is too big to email
Most email providers cap attachments at around 20–25 MB (Gmail is 25 MB, Outlook 20 MB). A PDF blows past that almost always because of embedded images — scanned pages, screenshots, or high-resolution photos — rather than the text, which is tiny by comparison.
That's good news: compression works by recompressing those images, so the text stays perfectly sharp while the file shrinks.
Compress it to fit
Open Compress PDF and start with the Medium setting — it noticeably reduces size while keeping everyday documents readable. Check the result; if it's still over the limit, re-run at High compression for the smallest file. For a document you're emailing rather than printing, High is usually visually fine.
When compression alone isn't enough
If a huge scanned document still won't fit even at High, split it. Split PDF breaks it into smaller files — chapters, or a page range — that you can send across two emails or attach individually.
Another option for a very image-heavy file: convert the pages to JPG with PDF to JPG at a moderate resolution, which can land smaller than the source PDF, then share those. And for anything genuinely large, a shared cloud link avoids the attachment limit entirely.