Open winmail.dat files privately
Read winmail.dat / TNEF and EML messages, view safe images, and download attachments without uploading them or installing Outlook.
Drop winmail.dat or EML files here
or choose them from your device
Up to 10 files · 25 MB each · 100 MB total · 300 extracted attachments
Files stay local. Anonymous task-step counting starts September 19 and never includes mail or attachment data.
Continuing after individual errors.
/ opened
What does this viewer do?
Mail File Viewer reads headers, bodies, inline images, and attachments from up to 10 winmail.dat TNEF or EML files directly in this browser. Remote images remain blocked until you allow them.
| Input | Up to 10 winmail.dat / TNEF or EML files |
|---|---|
| Safety limits | 25 MB each, 100 MB total, 100 MIME parts or attachments per source, 300 successful attachments per batch |
| Reading | Subject, sender, date, To/Cc summary, text or cleaned HTML, and inline images |
| Attachments | Image thumbnails, on-demand PDF preview, individual files or ZIP per source, plus an organized batch ZIP |
| Processing | Local browser memory; no upload or file-data tracking |
| Remote images | Blocked by default; loaded only for the current message after a click, without a referrer |
How to open a winmail.dat file in your browser
winmail.dat is a TNEF package. Microsoft Outlook sometimes wraps ordinary attachments in its Transport Neutral Encapsulation Format. Other mail apps may show only the wrapper instead of the files inside it.
- Choose or drop the file. Add one winmail.dat file or a batch of up to 10 TNEF or EML sources.
- Review the message. The browser reads its headers, safe body, inline images, filenames, and file types locally.
- Download the attachments. Save one file, a ZIP for the current source, or an organized ZIP for the successful batch.
Outlook is not required, and the selected mail never leaves this browser tab.
Your mail stays yours
There is no upload endpoint behind this page. Parsing, attachment downloads, and ZIP creation happen locally in this browser tab. Cloudflare counts page visits; beginning September 19, 2026, the viewer will also count three anonymous task steps. Neither receives filenames, mail or attachment content, file properties, results, full referrers, queries, or error details. There are no ads.
Useful details
Does the file really stay on my device?
Yes. The viewer has no file-upload code or server API. Selected bytes remain in this tab's memory until you remove or clear them, or close the page.
What can I extract?
The viewer displays readable email headers and text or cleaned HTML bodies. CID and Content-Location images use local Blob URLs; ordinary image attachments get thumbnails and PDFs can be previewed after a click.
Can it open MSG or EML files?
It reads EML and winmail.dat / TNEF files. It does not open MSG, EMLX, or MHT files.
Why was my file rejected?
Each source reports its own error if its TNEF or MIME structure cannot be parsed, it is truncated or damaged, has no readable content, exceeds 25 MB or 100 parts or attachments, or would take the successful batch above 300 attachments. Retry or remove that source; later files still run.