Open MDB and ACCDB files online — local Access viewer and Excel export
Turn a small Access database into a usable table package with clear evidence of what was read, skipped or represented differently. Your database stays in your browser.
Access Migration Desk
Try the real example: three related tables, Unicode, exact decimals, a long memo and one deliberately unread binary field.
Supported scope: One unlocked MDB/ACCDB up to 32 MiB; 100 local and 100 linked tables; 256 fields per table; 50,000 rows / 500,000 cells overall; 32 MiB decoded text, 2 million characters per cell. Local worker: 60 seconds, cancellable. No encrypted/password files, attachments, OLE, binary payloads, multivalue/calculated fields, macros, forms, queries or external linked data. Jet 3 text uses Windows-1252. ACE 15 is accepted by the engine but not independently fixture-verified in this release.
Choose an Access database
Required fields are marked with an asterisk.
Tables and export package
Review your output, then save it to your device.
Make the next step clear.
Your findings, assumptions and next steps will appear here after you run the check.
Access Migration Desk · https://access.kitforma.com/ · KitForma
Real MDB/ACCDB tables, not a file-name conversion
All local tables in XLSX, CSV and typed JSON
Field dictionary, relations and explicit loss report
Understand the evidence.
Focused guides explain the rules, the edge cases and the checks worth doing before you act.
Export Access tables to Excel without silently changing their values
Choose suitable representations for exact numbers, dates, empty values and long memos.
Read the guide ↗Field guide / 02Understand linked tables, attachments and relationships before migration
Separate local records from external sources and Access application features.
Read the guide ↗Field guide / 03Check an Access export for encoding, CSV changes and unread data
A practical verification sequence for a local database-to-table conversion.
Read the guide ↗Before you start
Can I open an MDB or ACCDB without Microsoft Access?
Yes, for supported local table data in an unlocked database. This browser reader produces real rows, field metadata and downloadable files. It does not run the Access application: forms, reports, queries and VBA are outside the export.
Is every table included in the Excel and CSV exports?
All readable local user tables within the limits are included, including empty tables. A catalog/readable row-count mismatch stops export. Linked tables are listed separately; their external rows are never fetched. Unsupported fields remain visible with explicit NOT EXPORTED markers.
What happens to attachments, OLE, binary and multivalue fields?
Their names and types appear in the field dictionary, but values are not decoded in this release. Calculated fields are also detected and omitted; export their evaluated values from Access. The JSON uses an explicit $unread object, and CSV/XLSX use a marker. Export these fields with Access or another suitable desktop tool before calling the migration complete.
Will Excel preserve large numbers, exact money and long memos?
Currency, decimal and BigInt are stored as text in XLSX and JSON to avoid Excel’s 15-digit numeric precision limit. Long memo strings over 32,767 characters are split into ordered _LongText chunks in XLSX; CSV and JSON keep the full string. Import CSV exact-number columns as text.
Can this remove a database password or repair corruption?
No. Password-protected and encrypted files are refused, including older MDB protection. A malformed file, unreadable table or row-count mismatch stops export. Open the original in Access and create a fresh unlocked copy or use its repair workflow yourself.
Which Access versions and encodings are supported?
The engine accepts Jet 3/4 and ACE 12/14/15/16/17 headers. Real fixtures in this release cover Jet 3/4 and ACE 12/14/16/17, not ACE 15. Jet 3 text is read as Windows-1252; non-Western legacy encodings need separate verification/export. Later formats use the engine’s Unicode decoding. Dates are text without an inferred timezone.
Sources & assumptions
Formats, algorithms and supported features are documented below. Check the stated scope and inspect your output before using it.
- mdb-reader — browser Access table reader ↗
Pinned MIT version 3.2.0. Reads Jet/ACE data with documented unsupported-field boundaries.
- Microsoft: Export Access data to Excel ↗
Native export remains useful for comparing values and extracting features outside this tool’s scope.
- Microsoft: Excel specifications and limits ↗
Excel cell text and numeric precision limits shape this tool’s long-text and exact-number export.
- Jackcess database library ↗
Independent Apache-2.0 reader/writer used to create and verify real MDB/ACCDB test fixtures. Not shipped as a browser dependency.
- OWASP CSV injection ↗
CSV formula-like text is prefixed; original text remains available in typed JSON and explicit XLSX string cells.
Reviewed 2026-10-18. Read our methodology or report an issue.