What Is an ACCDB File?

How to Open, Edit, and Convert ACCDB Files

Screenshot of several ACCDB files in Windows 10
ACCDB Files.

A file with the ACCDB file extension is an Access 2007/2010 Database file. It's the default format for database files used in the current version of MS Access.

The ACCDB file format replaces the older MDB format used in prior versions of Access (before version 2007). It includes enhancements to it like support for encryption and file attachments.

When you're working on an ACCDB file in Microsoft Access, a similar MS Access Record-Locking Information file (with the .LACCDB extension) is automatically created in the same folder to prevent from accidentally editing the original file. This temporary file is especially helpful when multiple people are using the same ACCDB file simultaneously.

How to Open an ACCDB File

Screenshot showing an ACCDB file open in MS Access
Opening an ACCDB File With Access.

ACCDB files can be opened with Microsoft Access (version 2007 and newer). Microsoft Excel will import ACCDB files but that data will then have to be saved in some other spreadsheet format.

The free MDB Viewer Plus program can also open and edit ACCDB files. This is a great alternative if you don't have a copy of Microsoft Access. Plus, it's totally portable, so you don't even need to install it.

Another way to open and edit ACCDB files without Access is to use OpenOffice Base or LibreOffice Base. They both let you connect to an existing Microsoft Access 2007 database (an .ACCDB file), but the result is a file saved in the ODF Database format (an .ODB file).

You can use MDBOpener.com to upload the ACCDB file online and view the tables without ever needing any database software on your computer. Though you aren't able to manipulate the database file in any way, you can download the tables in the CSV or XLS format.

ACCDB MDB Explorer for Mac can also open ACCDM and MDB files, but it's not free to use.

Note: You might need to install Microsoft Access Database Engine 2010 Redistributable if you're trying to use an ACCDB file in a program that isn't MS Access.

How to Convert an ACCDB File

Screenshot showing the formats MS Access can convert an ACCDB file to
Using Access to Convert an ACCDB File.

Using Microsoft Access is the best way to convert an ACCDB file to a different format. You can do this by opening the ACCDB file in Access and then saving the open file to a new format like MDB, ACCDE, or ACCDT (a Microsoft Access Database Template file).

You can also use Microsoft Excel to save the ACCDB file's table to a different format, but since Excel is a spreadsheet program, you can only save to that type of format. Some of the supported formats in Excel include CSV, XLSX, XLS, and TXT.

Whether you're using Access or Excel, you can convert an ACCDB to a PDF file using a free PDF printer like doPDF.

Keep in mind what I said above about the OpenOffice and LibreOffice software. You can use those programs to convert an ACCDB to ODB.

Follow the steps at Server Side Guy if you need to import an ACCDB file in Microsoft SQL Server.

More Information on ACCDB Files

If you're looking to use your access database with SharePoint or Outlook, you should use ACCDB over MDB because it supports the security requirements set in place by those programs.

When compared to MDB, ACCDB also allows for multivalued fields, meaning that you can store multiple values in each record without having to build a separate database.

There is a 2 GB maximum file size put in place for ACCDB files. Because ACCDB files support file attachments, they are automatically compressed to help keep the total file size under that limit.

Unlike MDB, the ACCDB format does not support user-level security. This means that you can't block off or hide certain areas of the database (e.g. a form) like you can when working in the MDB format.

ACCDB also does not support replication and cannot be opened or linked to using versions of Access prior to 2007.

What to Do If Your File Still Doesn't Open

Some file formats use file extensions that are spelled almost the same, use most of the same letters but in a unique arrangement, or even use all of the same letters. However, none of those circumstances necessarily mean that the formats are identical or even related at all, so it also means they don't necessarily open or convert in the same way.

For example, ACC files are used for both Graphics Accounts Data files and GEM Accessory files, but neither of those formats are the same and neither of them have anything to do with Microsoft Access. You most likely can not open an ACC file with any of the tools that work with ACCDB files.

The same is true for AAC, ACB and ACD (ACID Project or RSLogix 5000 Program) files. There are plenty of other file formats that could apply here, too.

If your file doesn't open with the above suggestions, try opening it in as a text document with a text editor like one from our list of the Best Free Text Editors. It's possible the very top or bottom, or anything in between, has some identifiable information that can help point you in the direction of what the format is, which can help lead you to a program that can open or convert your file.