What is an MSG file?
An .MSG file is primarily an Outlook Message Item File. It is created by Microsoft Outlook to store a single email, contact, appointment, or task. These files contain all message properties, including the sender, recipient, subject, date, and body text. They also store any file attachments included in the original email.
While most .MSG files are email messages, this extension is also used by some software and video games. For example, Bethesda Softworks uses .MSG files as Fallout In-Game Message Files to store text dialogues and game data.
How to open MSG files?
The standard way to open an .MSG file is with Microsoft Outlook on a Windows computer. If you do not have Outlook, you can use specialized email viewers, text editors, or online tools. Developers can read these files programmatically using libraries like MsgExtractor in Python.
Best practices and troubleshooting
If your .MSG file does not open as an email, it might be a game data file. Because the .MSG extension has multiple possible meanings, we recommend using viewer.online/msg to identify the actual format of your file.
If you need to share an Outlook message with someone who uses a Mac, Linux, or a mobile device, it is best to convert it. You can convert .MSG files to sensible target formats like .EML, .PDF, or .HTML on convert.guru to ensure easy access across all platforms.
Summary
viewer.online/msg analyzes .MSG files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. Because standard .MSG files use the known DOC (OLE Compound Document) format under the hood, viewer.online/msg can safely open and display them online, eliminating compatibility problems entirely.