Winmail.dat Opener App
Free app for opening winmail.dat attachments.

Android app on Google Play

Download from Windows Store

deutsch franšais

Online viewer for winmail.dat email attachments


Open winmail.dat or ATT0001.dat attachments with this free online extractor.

Step 1: Save the attachment on your computer.
Step 2: Click on the 'Browse' button and select the saved file.
Step 3: Click on 'Send file' to upload the file.
Step 4: Download the content of the .dat attachment from the results page.
Attachment upload:
Max. Size for uploads: 5MB


There a no results yet.

You first have to upload your winmail.dat file, than the content of the attachment will be listed here.

Depending on the size of your file and the speed of your internet connection this will take some time. The progressbar of your browser will indicate the progress of your file upload.

About this Service

What is a winmail.dat file?

If Microsoft Outlook is badly configured it sends attachments as a file called "winmail.dat" or "ATT0001.dat". This is a binary file and unusable with any other mail program except MS Outlook.

How to open winmail.dat files?

This service helps you to convert winmail.dat or ATT0001.dat files and extract the contained files. When you upload your winmail.dat attachment, we extract all contained files and save them for you to download them. After that, you can download the attached files from the results page.

Note: Not every winmail.dat attachment contains some files. Outlook saves also informations about layout and styling of an email into the winmail.dat file. This service is not able to extract images which are pasted directly into an email.

Privacy note

Privacy note

Using this service means that your files are transmitted over the internet and saved on a foreign system for a short time. If your attachment contains unencrypted, sensitive data it is not a good idea to use this service.

Your extracted files are saved on this system for some time so you can retrieve them. They are stored in a reasonably safe way so they names can't be guessed and will be deleted on your request or automatically after some time.

We do not intend to look at your files and try our best to protect your files from others doing that.

We use third-party advertising companies to serve ads when you visit our website. These companies may use information (not including your name, address, email address, or telephone number) about your visits to this and other websites in order to provide advertisements about goods and services of interest to you. If you would like more informations, click here.