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OST to MOBI converter

Convert OST to MOBI online from any device with a free converter.

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We have already processed 4,746,089 files with total size of 7,374,667 Mbytes

About Conversion app

Easily convert your OST files online with no registration required. Convert your OST documents from Windows, Linux, or macOS. Simply drag and drop your file into the upload form, select the desired output format, and click the convert button. Once the conversion is complete, you can download your MOBI file.

Depending on the OST file's size and format, conversion may take a few moments, but most files convert quickly. With advanced features, you can convert password-protected documents and have the results sent to your email.

Convert your OST documents anytime, anywhere, on any device—including mobile. Use this conversion app online 24/7—free for basic conversions.

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OST

Outlook Offline Storage File

An OST (Outlook Offline Data File) is a file format used by Microsoft Outlook to store a synchronized copy of mailbox data locally, enabling offline access to emails, calendars, contacts, and other items. It is primarily used by Microsoft Outlook and can be accessed or converted using tools like Kernel OST to PST Converter, Stellar Converter for OST, and SysTools OST Viewer. The OST file structure is based on the Messaging Application Programming Interface (MAPI) and supports advanced features like synchronization with Exchange Server, encryption, and data compression for efficient storage and security.

MOBI

Mobipocket eBook

The MOBI (Mobipocket eBook) file format is a popular eBook format designed for digital books and documents, originally developed by Mobipocket SA and later acquired by Amazon. It is supported by various e-readers, including Amazon Kindle devices, and can be created or converted using tools like Calibre, KindleGen, and Mobipocket Creator. The format supports features like bookmarks, annotations, and DRM protection, and its structure is based on HTML, allowing for text formatting, embedded images, and hyperlinks.

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APIs available

Convert popular document and image file formats in your app. The GroupDocs.Conversion APIs are available for .NET, Java, and many other platforms and languages.

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How it works

How to convert OST to MOBI

Step 1
Click inside the file drop area to upload OST file or drag & drop OST file.
Step 2
Click on Convert button. Your OST files will be uploaded and converted to MOBI result format.
Step 3
Download link of result files will be available instantly after conversion.
Step 4
You can also send a link to the MOBI file to your email address.
FAQ

Questions & Answers

Other Supported Conversions

You can also convert OST into many other file formats. Please see the complete list below.

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