Gmail and Outlook Attachment Size Limits (and What to Do)

Gmail allows attachments up to 25MB per message, according to Google's own Gmail help documentation. If your file is over that limit, Gmail automatically removes the attachment and replaces it with a Google Drive link instead, so your recipient can still access the file — you don't need to manually create the Drive link yourself in most cases.

For Google Workspace (business) accounts, admins can configure different limits, so if you're sending from a company account and hitting unexpected restrictions, that's worth checking with your workspace administrator rather than assuming the standard 25MB figure applies.

Outlook.com also allows attachments up to 25MB, per Microsoft's own support documentation. If you need to send something larger, Outlook.com supports sharing files via a OneDrive link of up to 2GB, which doesn't count against the 25MB attachment limit the same way a direct attachment does.

As with Gmail, Microsoft 365 business and enterprise accounts can have different limits set by an administrator, so your actual limit may vary if you're using a work or school account rather than a personal Outlook.com account.

The most common reason a PDF ends up oversized is that it's built from high-resolution scanned images rather than text — a handful of full-resolution phone photos converted into one PDF can easily add up to well over 25MB. Compressing the file typically brings it down significantly without making the content noticeably harder to read.