How to Make a PDF Small Enough to Email
Few things stall a quick email like an attachment that's too big to send. PDFs are common offenders, especially when they contain scans or photos. The fix is usually simple once you know the limits you're working against and the two ways to get under them.
Know the limits
- Gmail and Outlook cap attachments at around 20–25 MB.
- Many corporate mail servers are stricter, sometimes 10 MB.
- Going under 10 MB is the safe target that clears almost everything.
Compress first
Compression is the first move and usually the only one you need. Because a PDF's bulk is almost always its images, recompressing them and lowering their resolution to screen level can cut the file by 70–90% with no visible difference — text stays perfectly sharp. Compress once from the original for the best result.
Split if it's still too big
If a document is genuinely huge — a long scanned report — splitting it into two smaller PDFs and sending them separately beats fighting the limit. Or share a link instead of an attachment. Either way, compressing and splitting in your browser keeps the document off any server, which matters for sensitive files.
Frequently asked questions
How big can an email attachment be?+
Gmail and Outlook allow around 20–25 MB, but many corporate servers cap lower. Under 10 MB is the safe target.
What's the fastest way to shrink a PDF for email?+
Compress it. Since images are the bulk, recompressing them often cuts 70–90% of the size with no visible quality loss.
What if compression isn't enough?+
Split the PDF into smaller files and send them separately, or share a download link instead of attaching the file.