.MDI file extension
To open .MDI files on Windows, try opening the .MDI file with Microsoft Office Document Imaging (MODI) if it is installed (it’s the primary application associated with MDI).
To open a .MDI file, use Microsoft Office Document Imaging (MODI), which created and used the format. If you don’t have MODI available, the practical approach is to open it on a Windows PC with MODI installed or convert it to TIFF/PDF using a compatible tool or workflow.
Last updated: June 10, 2026
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .MDI files
Use these platform-specific instructions to open .MDI files safely.
Windows
- Try opening the .MDI file with Microsoft Office Document Imaging (MODI) if it is installed (it’s the primary application associated with MDI).
- If Windows asks what to use, choose MODI in “Open with”; if you don’t have it, your best option is to open the file on a PC that has MODI available or convert it to a more common format (such as TIFF/PDF) using a compatible conversion workflow.
Mac
- macOS does not commonly support .MDI files natively; if you can’t preview it, move the file to a Windows PC with Microsoft Office Document Imaging (MODI) to open or convert it.
- After conversion to TIFF or PDF, open the converted file in standard macOS apps.
Linux
- Linux typically won’t have built-in support for .MDI; if it doesn’t open in your viewer, transfer the file to a Windows system with MODI to open or convert it.
- Once converted to TIFF/PDF, open the result with your normal Linux image/PDF viewer.
iOS
- iOS usually can’t preview .MDI directly; transfer the file to a desktop (preferably Windows with MODI) to convert it to PDF/TIFF, then view the converted file on iOS.
Android
- Android apps commonly can’t open .MDI directly; move the file to a desktop (preferably Windows with MODI) to convert it to PDF/TIFF, then open the converted file on Android.
Security notes
- .MDI is an image/document format (TIFF-based) rather than an executable, but it still relies on complex file parsing; only open unknown .MDI files in trusted, well-known software.
- Be cautious with unexpected .MDI attachments: attackers can use malformed image/document files to target vulnerabilities in document imaging software. If you must inspect a suspicious file, prefer doing so on a non-critical machine and convert it to a safer, widely supported format afterward.
- Avoid “renaming to .tif” as a way to open it—this can confuse software and doesn’t actually convert the file; use the proper application/workflow to open and export/convert.
Can't open this file?
These are the most common causes and fixes when .MDI files fail to open.
Common reasons
- Windows can’t find an app to open the .MDI file
- The file opens but pages are missing or look corrupted
- macOS/Linux/phone won’t preview the .MDI file
Fix steps
- Check whether Microsoft Office Document Imaging (MODI) is available on the machine; it’s the most common program associated with .MDI.
- If you can’t install or access MODI, use a Windows system where MODI is available to open the file and convert/export it to TIFF or PDF for broader compatibility.
Recover a deleted or lost .MDI file
If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.
Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.
Wondershare RecoveritWindows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.
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OS-specific troubleshooting
What is a .MDI file?
.MDI is a proprietary Microsoft Document Imaging format used by Microsoft Office Document Imaging (MODI). Microsoft’s documentation describes it as a TIFF-based format designed to store page-layout images (often multi-page scans). The registered media type associated with this format is image/vnd.ms-modi.
Background
MDI (Microsoft Document Imaging) is primarily associated with Microsoft Office Document Imaging (MODI), a component of Microsoft Office shared tools. In real-world use, it commonly appears when older scanning or document-imaging workflows saved scans as MDI rather than TIFF.
Common MIME types: image/vnd.ms-modi
Further reading
Authoritative resources for more details on the .MDI format.
Common .MDI issues
Windows can’t find an app to open the .MDI file
This typically happens because Microsoft Office Document Imaging (MODI) isn’t installed, and MDI is not widely supported by default applications.
- Check whether Microsoft Office Document Imaging (MODI) is available on the machine; it’s the most common program associated with .MDI.
- If you can’t install or access MODI, use a Windows system where MODI is available to open the file and convert/export it to TIFF or PDF for broader compatibility.
The file opens but pages are missing or look corrupted
Because MDI is often used for multi-page scanned documents, incomplete transfers/downloads can show as missing pages or corrupted rendering.
- Re-copy or re-download the .MDI file to ensure it transferred completely (especially if it came via email or network share).
- Try opening it in Microsoft Office Document Imaging (MODI) and, if it loads, convert/export to TIFF/PDF to reduce future compatibility problems.
macOS/Linux/phone won’t preview the .MDI file
.MDI is tied to Microsoft Document Imaging and isn’t commonly supported on non-Windows platforms.
- Transfer the file to Windows and open it with MODI to confirm it’s valid.
- Convert it to TIFF or PDF for viewing on macOS, Linux, iOS, and Android.
FAQ
What does .MDI stand for?
MDI stands for Microsoft Document Imaging, the format used by Microsoft Office Document Imaging (MODI).
Is an .MDI file the same as TIFF?
Not exactly. Microsoft’s documentation describes MDI as TIFF-based, but it’s a proprietary format used by MODI and isn’t as widely supported as standard TIFF.
What is the MIME type for .MDI?
The registered media type associated with Microsoft Document Imaging is image/vnd.ms-modi.
Can I convert a file by renaming it to .MDI (or renaming .MDI to .TIF)?
No. Renaming only changes the extension text; it doesn’t convert the underlying file format. Use a proper open-and-export/convert workflow.
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