Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.MOBI
File Type
Mobipocket eBook
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .mobi file format
The MOBI file format is a proprietary ebook format developed by Mobipocket, based on the Open eBook standard. It was initially designed for mobile devices with limited processing power and storage. MOBI files can contain digital rights management (DRM) to protect copyrighted content. The format sup…
File extension
.MOBI
File type
Mobipocket eBook
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .mobi file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .mobi.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .mobi file?
File extension details and usage information
The MOBI file format is a proprietary ebook format developed by Mobipocket, based on the Open eBook standard. It was initially designed for mobile devices with limited processing power and storage. MOBI files can contain digital rights management (DRM) to protect copyrighted content. The format supports basic formatting, images, and annotations. It gained popularity due to its use by Amazon's Kindle devices before Amazon transitioned to its own AZW format, which is based on MOBI. While Amazon no longer directly supports MOBI for new Kindle content, it remains a widely used format for older ebooks and those distributed outside of the Kindle ecosystem. MOBI files can be read on various devices and platforms using dedicated ebook reader software. The format is relatively simple compared to more modern ebook formats like EPUB, but it remains a viable option for distributing text-based content.
Software Compatibility
Programs that may open or work with .mobi files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .mobi files be converted?
Options for saving or exporting this file to another format
In many cases, a .mobi file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .mobi file.
Why can't I open a .mobi file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .mobi format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .mobi files
To open a .mobi file, use software that supports this file format.
- Calibre
- Kindle for PC
- FBReader
- Sumatra PDF (limited support)
- Kindle for Mac
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .mobi file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.