MDE File (What It Is & How to Open One)

A file with the MDE file extension is a Compiled Access Add-in file used to store a Microsoft Access MDA file in binary format (or might be an add-in file used with architectural design software ArchiCAD to extend the program's functionality).

Advantages of MDE files include compacted file size, VBA code that can run but can't be changed, and the ability to edit data and run reports while shielding the user from having full database access.

What do you do if you need to open an MDE file? Below are some suggestions to help out.

Instructions in this article apply to Access 2019 and 2016.

How to Open an MDE File

MDE files can be opened with Microsoft Access and probably some other database programs as well. Here's how to open one in Access 2019:

Go to File > Open.
Select Browse if you don't see your file listed.
Search for the MDE file that you want to open, select it, and then choose Open.
You'll be warned of a potential security concern. If you know the source of the file, select Open, otherwise Cancel.
The MDE file should now be open in Access.

Import Your MDE File Into Excel

Microsoft Excel will import MDE files, but that data will then have to be saved in some other spreadsheet format like XLSX or CSV. Here's how to import an MDE into Excel:

Open or create a new spreadsheet.
Select the Data menu at the top of Excel and choose Get Data from the Get & Transform Data section.

If you don't see that option, choose Get External Data from the left side of the Data menu.
Select From Microsoft Access Database, or From Access if you see that instead.
Select and import the MDE file.
In Navigator, select the item(s) you wish to import. If you need more than one file, choose Select multiple items.
Select Load.
Wait for the data to import.
The information from the MDE file should now be in the Excel spreadsheet.

If you find that an application on your PC does try to open the MDE file but it's the wrong application or you'd rather have another installed program open MDE files, you can change the default program that opens MDE files in Windows.

How to Convert an MDE File

While there is some older information on how to convert an MDE to a MDB, Microsoft itself doesn't support this process. There's at least one company that will do the conversion for you at a cost.

Once the information in the MDE file is in the MDB format, you can convert the MDB file to ACCDB or ACCDE using Access.

Alternatively, you can open the MDE file in Access and then manually copy the data into a new MDB file.

Still Can't Open the File?

If the programs above aren't working to open your file, it's possible that you're misreading the file extension, meaning that you don't actually have an MDE file.

For example, an Amiga MED Sound file and RSView Development Project file both use the MED file extension, which is really similar to MDE but not the same. Even though they look like they might be related to Microsoft Access or ArchiCAD, they instead open with ModPlug Player and RSView, respectively.

The same is true for other file extensions that might sound or look like "MDE," like NOMEDIA. Another is MME, which belongs to the Multi-Purpose Internet Mail format, and MDD, which might be a Point Oven Deformation Data file or an MDict Resource file.