ACCDB file: what it is and how to open one

An .accdb file is a Microsoft Access database in the format Access has used since Access 2007, when it replaced the older .mdb. It holds tables of records and often the queries, forms and reports built on them. Access runs only on Windows and is not part of every Microsoft 365 plan, so plenty of people are handed an .accdb with nothing to open it. You do not need Access to read one.

Which program opens an .accdb file

• Windows, with Access 2007 or later: double-click it. Access 2003 and older cannot open .accdb at all, and older 2007+ versions refuse files that use newer data types (“Unrecognized database format”).
• Windows, without Access: Excel imports the tables (Data → Get Data → From Database → From Microsoft Access Database) if the Access Database Engine is installed. The free Access Runtime runs finished Access applications but hides the navigation pane, so it is a poor way to browse tables. On a work PC where you cannot install anything, see this guide.
• Mac: there is no Access for Mac (what works instead).
• Chromebook: what works.
• Linux: mdbtools reads many .accdb files, but its support for the newer format is partial.
• In Chrome on any of these computers: AccessLens opens .accdb files from Access 2007 to 2019 in a browser tab. Browse and search every table and export to CSV, Excel or SQLite, without uploading the file. Attachment and multi-valued columns show as marked placeholders and are left out of exports.

Password-protected .accdb files

Setting a database password in Access 2007 or later encrypts the file. If you have the password, Access asks for it when you open the file, and AccessLens does the same: it supports Access 2010 RC4 and Office Agile encryption, uses the password on your machine and never stores it. AccessLens does not recover or bypass passwords.

Converting .accdb to .mdb, Excel, CSV or SQLite

• To .mdb, for an older system: in Access, File → Save As → Access 2002-2003 Database. This fails if the database uses .accdb-only features such as attachments or multi-valued fields.
• To Excel or CSV: from Access (External Data → Export → Excel, one table at a time), with Excel's Get Data import, or with AccessLens, which needs no Access at all: Export → This table → CSV for one table, or Export → All tables → Excel workbook for every table in one file.
• To SQLite: AccessLens's Export → Whole database → SQLite (or SQL script) turns the tables into a SQLite database, or a script that builds one, which SQL tools open anywhere.

Files that travel with an .accdb

• .laccdb — a lock file Access creates while the database is open. It holds no data.
• .accde — a compiled, locked copy of a database, meant to be run in Access, with design views and VBA source removed.
• .accdr — a copy renamed so that Access opens it in runtime mode.

Questions