Spreadsheet File Formats

CLISC accepted file formats

Method	Input file formats	Output file formats
Count	.gsheet, .fods, .numbers, .ods, .ots, .xla, .xlam, .xls, .xlsb, .xlsm, .xlsx (Transitional and Strict), .xlt, .xltm, .xltx
Convert	.fods, .ods, .ots, .xls, .xlsb, .xlsm, .xlsx (Transitional and Strict), .xlt, .xltm, .xltx	.xlsx (Transitional)
Compare	Identical to Convert
Archive	Identical to Convert	.xlsx (Strict), .ods

CLISC unaccepted convert file formats

• .xla and .xlam are Microsoft Excel Add-in files and cannot contain worksheet cell information. Therefore, they are excluded from conversion but will be copied to the new archive directory, if archiving is selected.
• .gsheet is only a hyperlink to the file in cloud Google Sheets and cannot be processed. Instead, you receive an alert to manually handle the identified spreadsheet. They will not be copied, if archiving is selected.
• .numbers is a file format used in the Apple Numbers spreadsheet application, which is an app specific for the macOS and iOS operating systems. I have no experience with or care for the Apple ecosystem. I won't spend time on finding a solution at the moment. They will not be copied, if archiving is selected.
• .csv, .tsv and .xml may be used to store data originated from or being used in a spreadsheet app, but they may also be used as datasets or tables used in other contexts. Therefore, it is impractical to assume they are spreadsheets. They will not be copied, if archiving is selected.
• .123, .wks, .wk1, .wk2, .wk3, .wk4, .dif and .sxc were used by deprecated spreadsheet apps. These apps have been deprecated for over a decade and in most cases for much longer. They are not even included in the counting and they will not be copied, if archiving is selected.

If you don't agree with the above assessments, create an issue.

List of spreadsheet file formats

• Office Open XML (Excel) file formats: .xlam, .xlsb, .xlsm, .xlsx, .xltm, .xltx
• --> .xlam | Office Open XML Macro-Enabled Add-In | PUID | Wikidata
• --> .xlsb | Office Open XML Binary Spreadsheet | PUID | Wikidata
• --> .xlsm | Office Open XML Macro-Enabled Spreadsheet | PUID | Wikidata
• --> .xlsx | Office Open XML Spreadsheet (Transitional and Strict conformance) | PUID | Wikidata
• --> .xltm | Office Open XML Macro-Enabled Spreadsheet Template | PUID | Wikidata
• --> .xltx | Office Open XML Spreadsheet Template | PUID | Wikidata
• OpenDocument file formats: .fods, .ods, .ots
• --> .fods | OpenDocument Flat XML Spreadsheet | PUID | Wikidata
• --> .ods | OpenDocument Spreadsheet | PUID | Wikidata
• --> .ots | OpenDocument Spreadsheet Template | PUID | Wikidata
• Google Sheets file formats: .gsheet
• --> .gsheet | Google Sheeet | PUID | Wikidata
• Apple Numbers file formats: .numbers
• --> .numbers | Numbers Spreadsheet | PUID | Wikidata
• Delimiter separated file formats: .csv, .tsv
• --> .csv | Comma-Separated Values | PUID | Wikidata
• --> .tsv | Tabular-Separated Values | PUID | Wikidata
• Markup language file formats: .xml
• --> .xml | eXtensible Markup Language | PUID | Wikidata
• Legacy Excel file formats: .xla, .xls, .xlt
• --> .xla | Legacy Microsoft Excel Spreadsheet Add-In | PUID | Wikidata
• --> .xls | Legacy Microsoft Excel Spreadsheet | PUID | Wikidata
• --> .xlt | Legacy Microsoft Excel Spreadsheet Template | PUID | Wikidata
• Other legacy file formats: .123, .wks, .wk1, .wk2, .wk3, .wk4, .dif, .sxc
• --> .123, .wks, .wk1, .wk2, .wk3, .wk4 | Lotus 1-2-3 | PUID | Wikidata
• --> .dif | VisiCalc Data Interchange Format | PUID | Wikidata
• --> .sxc | OpenOffice 1.0 Spreadsheet (Sun XML Calc) | PUID | Wikidata

Microsoft VBA Office spreadsheet file formats

Another list by Microsoft, which describes the file formats they accept in VBA programming language when using Excel to transform spreadsheets to another file format.