Large source file
The PDF contains large images, scans, or exported slides.
PDF size limit guide
Compress PDF Under 25MB for Email and Uploads
A 25MB limit is common enough that users only notice it when an email attachment, portal upload, or client form rejects the PDF. The fastest fix is to reduce file size while keeping the document readable.
Last verified: July 18, 2026. Email and upload limits vary by provider, account type, and portal. Use the current attachment or upload prompt as the final rule.
Install onceBrowser workflowNo server storage
Why the upload failed
Upload errors usually come from files that are just over the limit, exported in the wrong format, or created from high-resolution scans and phone photos.
Upload target
The email or portal has an attachment cap around the selected file.
Portal mismatch
The document includes pages or image quality the recipient does not need.
Manual fix, then permanent fix
Remove blank pages, reduce image quality carefully, and export a smaller PDF that still keeps text and signatures readable.
Auto Compress helps prepare smaller PDFs in Chrome before the destination website receives them, and does not store files on Auto Compress servers for compression.
Check the prompt
Use the latest file-size and format rule shown by the upload portal.
Prepare a smaller file
Compress carefully so the document remains readable.
Upload normally
The destination website receives the smaller file. Auto Compress does not store it for compression.
Related backlinks
Useful Auto Compress guides
One extension for recurring upload limits