MOBI File Extension
Mobipocket EBook
- File Type mobi
- Developer Amazon
- Popularity
- Application Mobipocket Reader Desktop
- Category eBook Files
- Format Binary
What is a MOBI file?
Files with the MOBI extension are specifically tied to Mobipocket EBook, a eBook Files type, and there are 74 files in this category.
With the creation of the Mobipocket EBook (MOBI), Amazon introduced file format along with 5 programs built for their use.
MOBI files are compatible with various operating systems, including Windows, Mac OS and Linux. You can view a MOBI file using one of 14 programs, for example Mobipocket Reader Desktop, Amazon Kindle and Okular.
File Signature
HEX code: 42 4F 4F 4B 4D 4F 42 49. ASCII code: BOOKMOBI.
Programs that support MOBI files
Windows
Online Services
How to open a MOBI file?
The most common reason why a MOBI file cannot be opened is the absence of required software. To fix this, select a compatible program from the list. Then visit the official developer website via the provided link, download the program, and install it on your system.
Mobipocket Reader Desktop, Amazon Kindle and Okular are among the most widely used programs for handling MOBI files. To install the most up-to-date edition of Mobipocket Reader Desktop, visit the official Mobipocket website. You can download the build that works across all operating systems.
When you finish installing Mobipocket Reader Desktop, the system will automatically launch MOBI files with it.
Set Mobipocket Reader Desktop to open MOBI by default
Change default apps on Mac
- Right-click or use Control + Left-click on the desired MOBI file to access the file’s context menu;
- Choose "Open in Application" and click "Other";
- At the bottom of the window, you will see the "Enable" menu. It is already set to the default option, "Recommended Programs";
- Within this menu, select "All Programs" and then search for Mobipocket Reader Desktop. Check the box next to "Always open in app" to make it the default program.
Change default programs in Windows
- Start the process by right-clicking on your MOBI file and selecting "Open With". From there, click "Choose another app" to continue;
- Find the Mobipocket Reader Desktop application in the pop-up window and select it as your preferred program;
- Select the "Always use this application" check box and click "OK" to save your selection as the default application for opening MOBI files.
How to edit a MOBI file?
To modify MOBI files, it is necessary to install dedicated software that lets you open and edit ebook files. Online MOBI editors generally offer fewer tools compared to programs designed for Mobipocket EBook.
Best MOBI editors 2026
After analyzing the criteria, we have created a list of MOBI editors available for use.
| MOBI Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| eBooks Writer | Visual Vision | Windows | 4.3 out of 5 (37 reviews) |
Convert files to and from MOBI
When a MOBI file is not easy to work with, converting it to formats like MP3, PDF, RTF, EPUB, DOC or other comparable types may help.
It is important to understand that converting a MOBI file might limit certain functions, but this conversion is usually reversible.
Offline software options such as Epubor Ultimate Converter, Calibre and Hamster Free eBook Converter guarantee lossless conversion of MOBI files.
Convert MOBI to other file formats
Converting Files to MOBI Format
Easy MOBI Troubleshooting
When facing challenges with MOBI files, simple adjustments in your software can often solve the problem. Find helpful troubleshooting guidance below.
Are there any techniques or tools available to repair a damaged MOBI file?
Start a recovery program, open the damaged MOBI file and then select the "Repair" menu item to start the repair procedure. Wait for the recovery process to finish as it will automatically restore the damaged ebook files.
How can I confirm if my MOBI file has been damaged?
The signs of corrupted MOBI ebook files can manifest as:
- The file shows slow performance when edited in eBooks Writer;
- The file causes Mobipocket Reader Desktop or other software to hang or crash during various operations;
- The file encounters problems during the opening process or shows error indications;
- An unexplained increase in the size of the MOBI file;
- The file operation is accompanied by the display of error messages;
What factors contribute to Mobipocket Reader Desktop crash?
Lack of regular software updates can cause Mobipocket Reader Desktop to crash. Make sure you have installed the latest updates for Mobipocket products.
Restarting your computer is often an effective solution to resolve various common problems. Therefore, it is recommended to do so before making any changes to the software configuration.