Gmail caps attachments at 25 MB, Outlook at 20 MB by default, and plenty of corporate servers stop at 10 MB. If your PDF bounces, you don't need to split it across three emails. Compress it.
FernPDF's compressor re-encodes the document on your device. “Recommended” is visually lossless for most documents and typically gets image-heavy PDFs down 60% or more; “Strong” goes further when the deadline matters more than perfect image crispness.
Step by step
1Open the Compress PDF tool.
2Drop the PDF that's too big to send.
3Pick “Recommended”, then check the live size preview against your mail provider's limit.
4Download and attach. If it's still too large, re-run with “Strong”.
No upload · no account · no watermark
FAQ
Common questions
Under 25 MB for Gmail, under 20 MB for Outlook.com, and under 10 MB to be safe with corporate mail servers. The compressor shows the new size before you download.
“Recommended” is visually lossless for typical documents. Heavy compression mainly affects photographic images, not text sharpness.
No, compression runs in your browser. The file only travels when you email it.