Gmail's attachment limit is 25MB. That sounds like plenty, but it catches people regularly — especially with scanned documents, presentation decks, or PDFs with embedded photos. When you hit the limit, Gmail will not let you send the email, or it silently switches to a Google Drive link instead.
The 25MB cap is per email, not per attachment. If you are sending multiple PDFs in one email — say, a contract plus supporting documents — the total combined size has to stay under 25MB. That is where things get tight faster than expected.
For most business emails, keeping PDFs under 5–10MB is good practice regardless of Gmail's limit. Large attachments load slowly on mobile, get flagged by some corporate spam filters, and fill up recipient inboxes. A compressed PDF that still looks sharp is more considerate to send.
If you need to go significantly smaller — for a job portal or government form — use one of our targeted tools: 1MB, 500KB, or 200KB. For quality-first compression with no hard size limit, try Compress PDF Without Losing Quality.
Your file is either over 25MB, or your total email size including attachments and message body exceeds 25MB. Compress the PDF and try again.
This happens when your attachment exceeds 25MB. Gmail uploads it to Drive and replaces the attachment with a shared link. The recipient needs a Google account to open it. Compressing the file below 25MB lets you send it as a proper attachment.
Under 25MB for it to attach. Under 10MB to be considerate. Under 5MB if the recipient might open it on mobile.