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.
An HTM file is an HTML web page used by browsers such as Google Chrome, Microsoft Edge and Mozilla Firefox. Hyperlinks and a markup language that defines the elements and layout of a web page can be included.
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 HTM, and download the HTM 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 HTM 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
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These are the most polular file/document converters based on the user's review and usage on the FileProInfo.