U8MSG Other — A .u8msg file is a U8MSG Other. It is a file format typically read and written by specialized applications.
Quick facts
What is .u8msg
A .u8msg file is a U8MSG Other. It is a file format typically read and written by specialized applications.
In the mime-db registry it maps to message/global. When serving .u8msg over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to message/global — and is delivered over HTTP via the Content-Type header.
How to open .u8msg files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: message/global
Common software that reads/writes .u8msg:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .u8msg files
How to create .u8msg files
Frequently asked questions
Common options include VS Code, xxd, 7-Zip. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .u8msg extension.
message/global is the media type identifier used for .u8msg files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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