Is converting MDB to Oracle free?

Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.

Will my MDB data keep its types in Oracle?

Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real Oracle types rather than everything becoming text. The mapping table above shows exactly what you get.

Do you store my file?

No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.

Convert MDB to Oracle

Upload a .mdb or .accdb or .mde file and get back a Oracle SQL script you can load straight into your database. Types are preserved rather than flattened to text. Free, no registration, up to 10MB.

1Upload your file

Click to upload or drag and drop

CSV, Excel, SQLite, SQL, DBF (max 10 MB)

2Choose target format

How your data is typed in Oracle

Generated from the converter's own Oracle type mapping — this is what it actually emits, not an example.

Your data	Oracle type
Whole number	NUMBER(19)
Decimal (money)	NUMBER(10,2)
Floating point	BINARY_DOUBLE
True / false	NUMBER(1)
Date	DATE
Date and time	TIMESTAMP
Short text	VARCHAR2(255)
Long text	CLOB
Binary data	BLOB

Working from an .mdb file

An .mdb file is Jet 4, the engine Access used up to 2003. It is the format most likely to be sitting on a share drive with no copy of Access left in the building to open it - which is the situation this converter exists for.

→Jet 4 caps a database at 2 GB and a table at 255 columns, which is why an .mdb that has outgrown its purpose is usually a migration rather than a rewrite.
→There is no companion file to hunt for. A .ldb sitting beside the database is only a lock file from whoever last had it open, and nothing in it is needed - upload the .mdb on its own.
→Every table is read into memory in one pass before anything is written out, which is affordable only because the free upload is capped at 10 MB; a full-size Jet database would not be.

Oracle-specific edges in the script

Oracle diverges further from ordinary SQL than any other target here, and the script is shaped around that. Three of its choices are worth reading before you load, because each is a place where the source can hold something Oracle has no room for.

→Oracle's reserved list is full of words that legacy tables use as column names, so those get a trailing underscore: a column called DATE becomes DATE_, NUMBER becomes NUMBER_, LEVEL becomes LEVEL_.
→Binary values are written as HEXTORAW('...'), which a plain SQL script can carry only up to 2000 hex characters - 1000 bytes. Anything larger needs PL/SQL chunking that no portable script can express, so a table of real attachments moves better through the SQLite or DuckDB target.
→A string column of unknown length is declared VARCHAR2(4000) and anything longer becomes a CLOB. Under the default settings VARCHAR2 counts bytes rather than characters, so 4000 characters of Cyrillic or CJK will not fit in one.
→Rows are batched a hundred to a statement, each block closed off with SELECT 1 FROM DUAL, so a 100,000-row table arrives as a thousand statements rather than a hundred thousand.

Reading MDB

→Dates are exported in ISO form, avoiding the ambiguous 12/02/21 that Access tools produce by default.
→NULL and the empty string stay distinct.
→Access can hold dates outside the range it can represent. Those become NULL and the conversion tells you, rather than dropping them silently.
→Requires mdbtools on the server; if it is unavailable you get a clear error rather than a partial conversion.

Writing Oracle

→Uses INSERT ALL rather than multi-row VALUES, which Oracle rejects outright — the most common reason a generated Oracle script fails to load.
→Dates are written with TO_DATE and an explicit format mask.
→Booleans become NUMBER(1), because Oracle had no BOOLEAN column type before 23c.
→Identifiers are capped at 30 characters so the script loads on Oracle 12.1 and earlier too.
→Note that Oracle itself treats an empty string as NULL — that is Oracle behaviour, not a conversion error.

What you get

A ZIP containing dump.sql, plus a README with the exact command to load it. If anything about your data needed a judgement call, a _warnings.txt explains it.

Load this dump into Oracle:

  sqlplus USER/PASSWORD@//HOST:1521/SERVICE @dump.sql

Notes specific to Oracle:

  - Oracle treats an empty string as NULL. A column that held ''
    in the source will read back as NULL here. This is Oracle
    behaviour, not a conversion error, and it cannot be avoided.
  - Booleans are NUMBER(1), 1 or 0: Oracle had no BOOLEAN column
    type before 23c.
  - Identifiers are capped at 30 characters for compatibility
    with 12.1 and earlier.
  - Table and column names are quoted, so Oracle keeps their exact
    case. Unquoted Oracle identifiers fold to upper case, which
    means you must quote them in your queries too:
    SELECT * FROM "MyTable"; not SELECT * FROM MyTable;

Questions

Is converting MDB to Oracle free?: Yes. Files up to 10MB convert free with no account. There is a limit of five conversions per day per IP address.
Will my MDB data keep its types in Oracle?: Yes — that is the point. Whole numbers, decimals, dates and booleans are mapped to real Oracle types rather than everything becoming text. The mapping table above shows exactly what you get.
Do you store my file?: No. The file is written to a temporary directory, converted, and the directory is deleted as soon as your download has been sent.