What is an OTM file?
An .OTM file is most often an Outlook VBA Macro Project. Users create these files to automate tasks in Microsoft Outlook. The file stores custom scripts written in Visual Basic for Applications.
Because an .OTM file has multiple possible meanings, it might be something else entirely. It can act as a geographic analysis settings file for the U.S. Census Bureau OnTheMap application. Some .OTM files are OpenDocument Text Master Templates. Others function as an Origin Matrix Template used by OriginLab to process mathematical data matrices. Finally, the extension is also used for Yu-Gi-Oh! Omega deck files and OpenToonz animation projects.
How to open OTM files?
If you know the origin of your file, you can open it with its native application. Outlook macros require Microsoft Outlook. OpenDocument templates open smoothly in LibreOffice. Origin Matrix Templates open in Origin.
If you do not know the source of your file, viewer.online/otm analyzes .OTM files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
Software and tools
For advanced users, command-line tools can help identify the file type. Running the `file` command on Linux or macOS will tell you if the .OTM file is a Microsoft Compound Document, a ZIP archive, or a text-based JSON file.
If you have an OpenDocument Text Master Template, you might want to share it in a standard format. We recommend file conversion to sensible target formats on convert.guru, where you can change your template to a .DOCX or .PDF file.
Summary
viewer.online/otm directly opens and previews .OTM files in the browser, eliminating the need to install software or troubleshoot compatibility issues.