.MMR file extension

To open .MMR files on Windows, try opening the file with software that supports EDMICS-MMR/fax images (for example, Solvusoft reports FaxSee Pro as a program that can open .MMR files).

To open a .MMR file, use an image/fax viewer that supports Xerox/Fuji Xerox EDMICS-MMR images (often found on Windows). If you don’t have compatible software, try opening it on a desktop system first rather than renaming the extension.

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Last updated: June 11, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page

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Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps; we remove fantasy menus and unsafe shortcuts.
Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
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Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .MMR files

Use these platform-specific instructions to open .MMR files safely.

Windows

Try opening the file with software that supports EDMICS-MMR/fax images (for example, Solvusoft reports FaxSee Pro as a program that can open .MMR files).
If you already have an enterprise capture/fax application from the source workflow, open the .MMR from within that application (File → Open/Import).
If Windows prompts “Choose an app,” select the compatible viewer and enable “Always use this app” only after you confirm it opens correctly.

Full Windows guide

Mac

If Preview does not open the .MMR file, you likely need specialized fax/document imaging software; macOS commonly lacks built-in support for this format.
If you received the file from a business system, ask the sender for the recommended viewer or an export to a more common format (e.g., TIFF/PDF) from their system.
As a workaround, transfer the file to a Windows PC or the originating workflow environment where EDMICS/fax-viewer support is more likely.

Full Mac guide

Linux

Try opening the .MMR file using any installed document-imaging/fax viewing tools you already use in your workflow; many desktop image viewers may not support EDMICS-MMR.
If it does not open, use the originating system (or a Windows machine with a compatible viewer) to convert/export it to a standard format like TIFF or PDF.
If you manage a server workflow, verify the file’s MIME/format identification first; the expected MIME type is image/vnd.fujixerox.edmics-mmr.

Full Linux guide

iOS

iOS Files/Quick Look typically won’t preview specialized .MMR fax images; open it only if you have a specific app from your workflow that explicitly supports EDMICS-MMR, otherwise move it to a desktop for viewing/conversion.

Full iOS guide

Android

Android’s built-in viewers usually won’t open .MMR; if you don’t have a dedicated fax/document imaging app that supports it, transfer it to a desktop system for viewing or conversion to TIFF/PDF.

Full Android guide

Security notes

.MMR is an image format (bitonal document imaging), not a script or macro format, but it is still safest to open only files from trusted sources because malformed image data can sometimes trigger vulnerabilities in parsers/viewers.
Be cautious with unexpected .MMR attachments claiming to be invoices or faxes; if you don’t recognize the sender or workflow, request a re-send in a standard format (PDF/TIFF) through a trusted channel.
Prefer opening .MMR files in well-maintained, reputable viewers; avoid obscure “one-off” converters from unknown vendors, since document-image parsers run on untrusted input.

Complex decoders and untrusted media

Image, audio, and video decoders are large software surfaces; issues are uncommon for everyday files but show up with crafted files from unknown sources. Keeping the OS and media apps updated matters most; scanning is reasonable extra caution for downloads you cannot vouch for.

Avast

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Norton

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Can't open this file?

These are the most common causes and fixes when .MMR files fail to open.

Common reasons

No app can open the .MMR file
The file opens but looks blank or corrupted
Wrong file type: .MMR doesn’t match the contents

Fix steps

Open it using a viewer known to support EDMICS-MMR images (Solvusoft reports FaxSee Pro as an option on Windows).
If the file came from a business/fax system, use that system to export/convert the image into TIFF or PDF for easier viewing.

OS-specific troubleshooting

What is a .MMR file?

.MMR typically refers to an EDMICS-MMR bitmap/image file that stores bitonal (black-and-white) imagery compressed with MMR (Modified Modified READ), also known as CCITT Group 4 fax compression (ITU-T T.6). The IANA-registered MIME type for this family is image/vnd.fujixerox.edmics-mmr, and .mmr is a commonly associated extension.

Background

MMR (Modified Modified READ) is a well-known compression method for black-and-white images, widely associated with fax imaging as CCITT Group 4 (ITU-T T.6). It is designed for efficient storage/transmission of bitonal scans such as documents and forms.

In practice, .MMR files are most often encountered in document imaging, fax, or enterprise capture workflows. Multiple sources associate the extension with Fuji Xerox/Xerox EDMICS-related bitmap images and the vendor media type image/vnd.fujixerox.edmics-mmr.

Because .MMR is specialized and not a mainstream consumer photo format, many default photo apps will not open it. The most reliable approach is to use software known to handle fax/document imaging formats or to open it in the same system that produced it (e.g., an EDMICS-related workflow).

Common MIME types: image/vnd.fujixerox.edmics-mmr

Common .MMR issues

No app can open the .MMR file

Many standard photo viewers don’t support EDMICS-MMR/Group 4 fax image containers, so the OS may report the file is unknown or unsupported.

Open it using a viewer known to support EDMICS-MMR images (Solvusoft reports FaxSee Pro as an option on Windows).
If the file came from a business/fax system, use that system to export/convert the image into TIFF or PDF for easier viewing.

The file opens but looks blank or corrupted

MMR is typically for bitonal document scans; if the file is incomplete, damaged, or interpreted with the wrong assumptions, it may render incorrectly.

Re-download or re-transfer the file (binary-safe transfer) and confirm the file size matches what the sender provided.
Try opening it in the software/workflow that created it; if that works, export to a standard format for sharing.

Wrong file type: .MMR doesn’t match the contents

Some files may be mislabeled with the .MMR extension; general-purpose programs will fail if the bytes don’t match an EDMICS-MMR image.

Check the sender/source system documentation for what the file is supposed to be (fax/image export vs. something else).
If possible, have the sender re-export the document to a standard format (TIFF/PDF) rather than renaming extensions.

FAQ

What does .MMR stand for in image files?

It commonly refers to MMR (Modified Modified READ), the CCITT Group 4 fax compression method used for black-and-white (bitonal) document images.

What is the MIME type for .MMR?

The IANA registry lists the vendor media type image/vnd.fujixerox.edmics-mmr, which is associated with .mmr in multiple references.

Can I fix it by renaming .MMR to .TIF or .PDF?

No. Renaming only changes the extension; it doesn’t convert the internal data. Use the originating system or a compatible viewer/converter to export to TIFF/PDF.

Why won’t my phone open a .MMR file?

MMR/EDMICS-MMR is a specialized fax/document image format and is often unsupported by built-in mobile viewers. A desktop workflow is usually the easiest way to view or convert it.

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