Drop file here. 150 MB maximum file size.
An OST file is a data file created by Microsoft Outlook (2005 or later), an email client and a manager; personal information. It is used to store a copy of the mailbox information; an Office 365 account, Exchange or Outlook.com. The files may contain e-mails, contacts, tasks, calendar data and other account information.
A DOTM file is a document created by Microsoft Word, a word processing program. Contains the default layout, settings and macros d' a document. DOTM files create a new .DOCM document with built-in macros.
Access powerful and secure free online OST tools to convert, view, edit, merge, split, and compare OST files β all without installing any software. Our tools support the .OST (Outlook Offline Data File) file extension and run smoothly in any modern browser.
Select a tool below to explore features and manage your OST files directly from your device with ease.
Chose or drag & drop your OST file, click Convert to DOTM, and download the DOTM file. No registration needed.
Yes, all uploads are encrypted. Your files are auto-deleted after 24 hours.
Yes, our converter retains layout, fonts, and images as accurately as possible.
Fileproinfo converter engine works fast. You can convert OST to DOTM in a few seconds to couple of minutes for large size files with complex structure.
FileProInfo support manay file formats that allow you to convert OST to 100s of file formats, without any limit, registration and downloading, 100% free and online OST converter.
All converters in this list are manually verified & 100% free and working properly, however you must use these apps according to their respective terms & conditions.
This tool and page updated at: 12-Apr-2025
About FileProInfo: FileProInfo is a trusted platform dedicated to file formats and software programs. We provide accurate technical details, easy-to-use navigation, and advanced search capabilities to help users explore, manage, and convert file types efficiently.
Listed file converters are from the wide range of online file converter.
These are the most polular file/document converters based on the user's review and usage on the FileProInfo.