What is the DBT file format?
A .dbt file is the memo sidecar to a .dbf dBASE table - it stores the variable-length text or binary content for memo-type fields defined in the accompanying .dbf. Because dBASE's fixed-length record structure cannot accommodate long text directly, memo fields in the .dbf store only a block-number pointer; the actual text lives in fixed-size blocks inside the .dbt.
The format originated in the early 1980s with dBASE III (Ashton-Tate) and was later used by Clipper, dBASE IV, and compatible tools. dBASE III used fixed 512-byte blocks with records terminated by two 0x1A bytes. dBASE IV retained the 512-byte default but added a variable block-size word in the header and a per-memo length prefix.
A .dbt file is never standalone: without its paired .dbf the block addresses are meaningless and the data cannot be read. FoxPro and Visual FoxPro replaced .dbt with their own .FPT memo format. Modern databases handle variable-length text as inline BLOB or TEXT columns, making both formats largely obsolete.
Recovering data from an orphaned or corrupt .dbt requires specialized DBF recovery tools or manual hex inspection, since the block structure and codepage (typically CP437 or CP1250) must be known.
Security & safety
RISK: LOWA .dbt is inert data - no executable code - so it is safe to open. The real risk is data loss: separating a .dbt from its .dbf, or restoring only one of the pair from backup, orphans the memo text. Always back up and move .dbf + .dbt (and any .cdx/.mdx index) together.
Format details
in a nutshell- Sage ACT! database support file - Older ACT! contact-manager installations used dBASE-family files including .dbt.
- Generic database text/template file - Some legacy tools labelled assorted database text or template files .dbt.
Programs that open DBT files
Windows4 apps
LibreOffice Calc / Base
Open-source Open the .dbf; LibreOffice reads the paired .dbt memos. Keep both files together.
DBF Viewer 2000 / DBF Commander
Paid Open the .dbf to browse records including memo fields stored in the .dbt. 
macOS1 app
Linux1 app
Technical details
deep spec| Encoding | Binary container holding text records (usually ASCII/OEM codepage, typically CP437 or CP1250) |
| Byte order | Little-endian |
| Container | dBASE memo block file (sidecar to a .dbf table) |
| Typical size | Few KB - tens of MB (depends on the volume of memo text in the table) |
| Block size | Fixed 512-byte blocks in dBASE III; configurable block size stored in the header for dBASE IV |
| Record terminator | Two 0x1A bytes mark the end of each memo record in dBASE III format |
| Structure | Header block plus fixed-size data blocks; .dbf memo fields store a 32-bit block number pointing into the .dbt |
| Memo addressing | 32-bit block numbers in the .dbf field index into the .dbt; the two files are inseparable |
| Associated OS | DOS, Windows |
| Superseded by | .fpt format in FoxPro and Visual FoxPro; inline BLOB/TEXT columns in modern databases |
| Released | 1980s (dBASE II/III memo support) |
| Latest version | dBASE IV memo layout (variable block size); FoxPro uses .fpt instead |
| Open standard | Yes · royalty-free |
| Specification | www.dbase.com |
DBT conversions
Community Q&A
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