What is the BTR file format?
A .btr file is a Btrieve database file - a proprietary Indexed Sequential Access Method (ISAM) data store that originated in 1982, initially targeting CP/M and DOS. Btrieve became one of the dominant small-business database engines of the 1980s and 1990s, powering accounting and practice-management software from vendors including Sage, MYOB, and Peachtree.
The format uses a page-based architecture with fixed-size pages (512 bytes to 4 KB in classic versions; up to 16 KB in PSQL v9 and later). The first page is the File Control Record (FCR), storing page size, format version, and key configuration. Subsequent pages hold embedded B-tree index structures and data records - all within the single .btr file rather than in separate index files, simplifying deployment.
Btrieve's ownership history is complex: WordPerfect Corporation acquired Btrieve Technologies, Novell then acquired WordPerfect, Pervasive Software later obtained the technology, and Actian Corporation acquired Pervasive in 2013. The product continues as Actian PSQL v15, with the BTRv9 64-bit file format supporting databases several terabytes in size.
Record-level compression was added in Btrieve 6.x; AES encryption arrived with PSQL v11; optional page-level checksums became available in PSQL v9.5. Many organizations still running legacy .btr databases are actively migrating workloads to SQL Server or PostgreSQL, though Actian PSQL remains commercially supported.
Security & safety
RISK: LOWBtrieve files are data-only databases; they do not execute code. Older encryption (owner-name XOR) is weak and not a security guarantee. Standard database access controls apply for server-based deployments.
Format details
in a nutshell- Microsoft FrontPage Web - FrontPage Server Extensions used .btr files as web configuration databases (identified in db_name as 'Microsoft FrontPage related file' - this is a secondary use, not the primary format).
Programs that open BTR files
Windows3 apps
Pervasive Btrieve Database Manager
Paid Legacy management tool; current equivalent is Actian PSQL Control Center.
Actian PSQL (formerly Pervasive PSQL)
Paid Use Actian PSQL Workgroup or Server edition to open .btr databases via the native Btrieve API or ODBC driver.
BTRIEVE Viewer (dbfviewer.com)
Freemium View and export Btrieve table data without requiring PSQL server installation. Technical details
deep spec| Format type | Proprietary page-based ISAM (Indexed Sequential Access Method) database |
| Byte order | Little-endian |
| Page sizes | 512 B - 4 KB (classic); up to 16 KB (PSQL v9+) |
| First page | File Control Record (FCR): page size, format version, key configuration |
| Index structure | Embedded B-tree (indexes co-located within the .btr file; no separate index files) |
| Compression | Optional record-level compression (Btrieve 6.x+) |
| Encryption | AES (PSQL v11+); older versions use proprietary XOR-based owner-name encryption |
| Integrity check | Optional page-level checksums (PSQL v9.5+, enabled per-file) |
| File format versions | 5.x, 6.x, 7.0, 8.x, 9.x (BTRv9 with 64-bit support), 10.x-15.x (Actian PSQL) |
| Typical size | Few KB to several GB; multi-TB possible with BTRv9 |
| MIME type | application/octet-stream |
| Associated OS | Windows; Linux (Actian PSQL server) |
| Current product | Actian PSQL v15 (successor to Pervasive PSQL) |
| Concurrency model | Page-level locking (classic Btrieve); transaction logging supported in PSQL |
| Released | 1982 (Btrieve 1.0 for CP/M and DOS) |
| Latest version | Actian PSQL v15 (2020s); BTRv9 file format (Btrieve 9.x+) |
| Specification | docs.actian.com |
BTR conversions
Community Q&A
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