Why convert ACCDB to MDB?
MDB is the Access format used by versions 97 through 2003 (Jet engine), while ACCDB requires Access 2007 or later (ACE engine). Converting to MDB allows older Access installations and legacy software - such as accounting systems and reporting tools predating the 2007 format change - to open the database.
How to convert ACCDB to MDB
Microsoft Access APP
Open the .accdb file, go to File > Save As, and select Access 2002-2003 Database (*.mdb). Access will warn you if any ACCDB-only objects block the save; remove those objects and retry.
Programs that convert ACCDB
About these formats
.ACCDB
Microsoft Access Database (2007+)
An ACCDB file is a Microsoft Access database - the format Access has used since the 2007 version, replacing the older .mdb. It stores tables, queries, forms, reports, and VBA code in one…
Open .ACCDB details →
.MDB
Microsoft Access Database (97-2003, Jet engine)
An MDB file is a Microsoft Access database in the old format Access used from 1992 through 2003, replaced by .accdb in Access 2007. It stores tables, queries, forms, reports, and VBA code…
Open .MDB details →Quality & what to watch
- The save fails if the database contains multivalued fields, attachment fields, calculated columns, or data macros - those must be deleted or converted to compatible types first.
- Standard tables, queries, forms, reports, standard macros, and VBA modules all convert without issue.
- MDB supports workgroup-based user-level security (dropped in ACCDB) - if needed after conversion, it must be reconfigured from scratch using the Workgroup Administrator tool.
Frequently asked questions
Which Access versions can open MDB files?
.mdb files.What happens if my database uses multivalued fields?
Does converting to MDB change the original ACCDB?
.accdb remains unchanged.
