Example attachments
A safe Winmail.dat example with two harmless attachments.
Free · Private · No signup
Open Winmail.dat files online
Decode Outlook TNEF attachments and download the original documents, images and calendar files without installing an app.
Private by designYour Winmail.dat file is decoded locally in this browser. It is never uploaded to our server.
Example result2 extracted attachments
winmail.datDecoded locally · Not uploaded
What does the viewer extract?
Winmail.dat may contain the formatted email body, file attachments, meeting invitations and Outlook-specific information. FormatPeek lists every readable embedded file and lets you download it separately.
Is my file uploaded?
No. Decoding happens locally in your browser, so the file and its extracted contents are not sent to FormatPeek’s server.
Why did I receive Winmail.dat?
Microsoft Outlook and Exchange can package rich-text email information in Microsoft’s TNEF format. Some other email apps show that package as a mysterious Winmail.dat attachment instead of revealing its contents.
Read the complete Winmail.dat format guide.