About us
A small tool for an annoying email problem.
Winmail.dat Opener exists to make one frustrating file format easier to understand and safer to handle.
Why this exists
Some email clients package rich-text formatting and attachments inside a TNEF container named winmail.dat. When your mail app cannot read that container, a useful attachment can look like an unreadable .dat file.
What we built
This site is a focused browser utility: choose the file, decode it locally, and save the attachments you need. It is intentionally small, clear, and free to use.
Privacy by design
The decoder processes the selected file in your browser instead of requiring a file upload or account. That keeps the workflow quick and gives you a clearer boundary around your data.
Keep in touch
If the tool helped or you found a file it cannot open, we welcome practical feedback. The contact page explains what details are useful and how to reach us.