Free online XLSX to MDB converter

Legacy Microsoft Access applications may require an .mdb database and reject an Excel workbook. Converting the workbook imports its worksheets as database tables that can be queried, indexed, and edited in Access-compatible software.

What the XLSX format is

.xlsx is the XML-based workbook format introduced with Microsoft Excel 2007 and used by current Excel versions. Microsoft Excel, LibreOffice Calc, reporting systems, and spreadsheet applications that export Excel files use it. An XLSX workbook can contain multiple worksheets, formulas, charts, tables, formatting, and named ranges, but its structure is intended for spreadsheet calculations rather than relational database operations.

What the MDB format is

.mdb is the Microsoft Access 2000–2003 database format, built for the Jet database engine. One MDB file can contain tables, relationships, indexes, queries, forms, reports, and macros. Its main practical advantages are compatibility with legacy Access software, a single-file database container, and support for relational queries and indexed fields. Newer Access versions normally use .accdb, but they can generally open or create MDB files when the required legacy features are supported.

How to convert an XLSX workbook to MDB

Microsoft Access provides the most control because it lets you choose worksheets, inspect field types, and define keys and relationships.

1. Open Microsoft Access and create a blank database. If the final file must be MDB, create or save the database in an Access 2000–2003 format when that option is available.
2. Choose External Data → New Data Source → From File → Excel.
3. Select the .xlsx workbook and choose Import the source data into a new table in the current database.
4. Select the worksheet or named range to import. Enable First Row Contains Column Headings if the first row contains field names.
5. Review the proposed field names and data types. Define a primary key, or let Access add an ID field if the source has no unique identifier.
6. Repeat the import for every worksheet that should become a separate table.
7. Check the imported records, then select File → Save As → Access 2000–2003 Database (*.mdb). Depending on the Access version, the command may appear under File → Save As → Save Database As.

For a conversion without installing desktop software, the built-in converter on 101convert.com can convert the file for free. Access is preferable when the database needs selected worksheets, corrected field types, primary keys, indexes, relationships, queries, or other database objects.

Compatibility and data quality limits

• This process is an import into a database, not a direct rewrite of the XLSX container. A selected worksheet normally becomes an MDB table; charts, cell formatting, conditional formatting, and workbook layout do not become Access objects.
• Formula cells may be imported as their calculated values rather than as reusable Access expressions. Recreate required calculations with Access queries, expressions, or calculated fields.
• Access infers field types from spreadsheet content. Mixed numbers, dates, and text in one column can produce incorrect types or cause incompatible values to be discarded. Clean each column and keep its values consistent before importing.
• Worksheet names, column headings, blank rows, duplicate headings, and characters that are invalid in Access field names may be changed or rejected. Compare row counts and important values after conversion.
• Relationships are not reliably inferred merely because worksheets contain columns with matching names. Create primary keys, foreign keys, relationships, and indexes manually after importing the tables.
• An MDB database has a maximum file size of approximately 2 GB. Older Jet and Access versions also have limits on field types, table design, queries, and concurrent use. Split a large import or use a newer database format when the MDB limit or legacy feature set is insufficient.