The Genstat spreadsheet file format (.gsh) has been extended with each new version of Genstat to include the latest features. Unfortunately this creates compatibility problems when data are exchanged between different versions of Genstat. However, changes to the format have been designed to minimize these problems. In particular, .gsh version 3 includes spare capacity that can be used by later versions of Genstat when additional features are added. These spare items are ignored when reading in earlier versions, and set to default values when written by an earlier version.
A multi-paged book format (Genstat workbook – .gwb) is available from the Ninth edition onwards. This format allows multiple spreadsheets to be saved within the same file. In addition to this the ability to compress .gsh formats is available from the Ninth edition onwards (controlled using the Tools | Spreadsheet Options Save tab).
To minimize problems when sharing data between different Genstat versions, the File | Save As menu lets you specify the format to be used. Thus it is always possible to save a .gsh file in an older format.
A new version of the .gsh format (version 4) which was introduced in the Fifteenth edition. This is backwards compatible to the Ninth edition as it uses the more compact .gwb format internally.
Compatibility between file versions and Genstat editions is summarized in the following table.
| Genstat Edition | First | Second | Third-Eighth | Ninth-Nineteenth |
| gsh version 1 |  |
|
|
|
| gsh version 2 | |
|
|
|
| gsh version 3 | |
|
||
| gsh version 3 (compressed) | |
|||
| gsh version 4 | |
|||
| gsh version 4 (compressed) | |
|||
| gwb version 1 | |
|||
| gwb version 1 (compressed) | |
The multi-page .gwb and compressed .gsh formats are not backwards compatible and can only be used in the Ninth edition or later. For backwards compatibility with earlier versions of Genstat, you will need to save spreadsheets individually using .gsh version 3 (uncompressed). If you need to save data in a form that can be read by the First or Second edition you will need to save it in version 1 or 2 as appropriate.
The maximum length for a factor label was increased from 40 to 60 characters in the Tenth edition, and increased further to 90 characters in the Seventeenth edition. Opening a .gsh or .gwb file with factor labels over 60 characters within the Sixteenth edition or earlier will produce a warning and truncation of the labels.
The maximum length of a text was increased from 60 to 90 characters in the Third edition, and to a user specified maximum (fewer than 10,000) in the Tenth edition. Opening Tenth edition .gsh and .gwb files with texts over 60 characters long will result in warnings in earlier versions of Genstat, but the file will still open.
The maximum number of columns supported in one sheet was increased from 16,000 to 50,000 in the Sixteenth edition. The maximum number of columns for a sheet can be set within the Tools | Spreadsheet Options Sheets tab. If a data set contains more than 50,000 columns you can split the data across more than one sheet within a book.
The maximum length of a column name was increased from 40 to 60 characters in the Sixteenth edition. Opening Sixteenth edition onwards .gsh or .gwb files with column names over 40 characters may result in warnings in earlier versions of Genstat, but the file will still open.