Outlook attachment size limit

Get any file to the size you need. Privately.

1 Shrink your PDF locally to under 20 MB.2 Attach the compressed copy in Outlook.3 Send directly without triggering OneDrive prompts.

About this tool

Microsoft Outlook limits email attachments to 20 MB or 25 MB depending on server config. When a file is too large, Outlook blocks delivery or prompts for OneDrive. Compressing your PDF locally before attaching keeps the document beneath the threshold without sending files to external sites.

Outlook attachment size limit stays on this device. The download is the copy you keep, and Weesize does not store a second one. Close the tab when you are finished and the bytes are gone.

  • No upload: local processing keeps your email attachments private.
  • Speed: the file does not travel to a server and back, so the wait is only the work itself.
  • Quality: the original is kept when the new file would be worse or is not actually smaller.
FAQ
Does “Outlook attachment size limit” upload my file?

Outlook attachment size limit reads the file in this tab. There is no upload step and no account.

What will “Outlook attachment size limit” actually change?

Outlook caps default attachments at 20–25 MB.

When is “Outlook attachment size limit” the wrong job?

Local compression shrinks images inside the PDF without uploading.

How do I check the result of “Outlook attachment size limit”?

Review pages before sending important contracts.

Can I run “Outlook attachment size limit” with Wi-Fi off?

Load this page, then turn Wi-Fi off and run Outlook attachment size limit again. A finished result is the proof that the file was not sent anywhere.

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Last updated 2026-09-27.