Free online OPUS to ABC converter

Conversion is needed when records stored in an OPUS database must be opened by software that accepts the ABC database format. Because both extensions can identify application-specific database files, the source and target programs must be confirmed before any conversion.

What the OPUS format is

In the Databases category, .opus refers to an OPUS application database, not an audio recording. It stores structured records in a format defined by the OPUS software that created it. The extension is not a universal database standard, so different OPUS products or versions may use incompatible internal structures.

You usually encounter an OPUS file when it has been copied from an older business, cataloguing, records-management, or specialist database installation. The creating OPUS program is the most reliable way to identify its schema, required indexes, linked files, and export options.

What the ABC format is

In the Databases category, .abc denotes an ABC application database file rather than a general-purpose interchange format. Its tables, field types, indexes, relationships, and encoding depend on the ABC software that opens it.

ABC is useful when the destination application specifically requires its native database format. It may preserve application-specific structures that a plain CSV export cannot, but it is generally less portable than CSV, SQL, XML, or JSON because other database programs may not understand the file.

How to actually convert OPUS to ABC

There is no dependable format-only conversion unless the installed OPUS and ABC products document compatible import and export functions. Use this workflow:

1. Make a backup of the original .opus file and any companion files in the same directory. Do not work on the only copy.
2. Open the file in the OPUS application that created it. If it is rejected, identify the exact product and version from the file's source, documentation, or the operating system's file association.
3. Use File → Export or the product's database tools to export each required table. Prefer CSV for simple records, or SQL, XML, or another documented structured format when relationships, dates, or repeated fields must be retained.
4. In the ABC application, use File → Import or its table-import utility and select the exported files. If ABC accepts only its own database file, create a new empty ABC database first, then import or paste the records into its tables.
5. Map OPUS columns to ABC fields, including primary keys, date formats, Boolean values, character encoding, and required fields. Recreate relationships and indexes in ABC rather than assuming they survived a flat-file export.
6. Compare record counts and sample records, then test searches, sorting, reports, and linked records in ABC before archiving or deleting the OPUS data.

You can also try the free converter on 101convert.com without installing software. It can convert the file only when its service supports the particular OPUS and ABC variants; a generic extension match cannot translate an undocumented proprietary database structure.

Quality, compatibility, and limitations

Direct conversion may be impossible when the OPUS format is proprietary, encrypted, damaged, or tied to a discontinued application. Renaming .opus to .abc changes only the filename and does not convert the database.

CSV export commonly loses indexes, relationships, forms, reports, validation rules, attachments, and application metadata. Check non-ASCII characters after import and preserve leading zeros in identifiers by importing those columns as text. If the OPUS software can export SQL or XML with schema information, that option usually preserves more structure than CSV.