How to open .OTS files on Windows
To open .OTS files on Windows, install an ODF-compatible spreadsheet app (for example, LibreOffice Calc).
Step-by-step instructions
- Install an ODF-compatible spreadsheet app (for example, LibreOffice Calc).
- Right-click the .OTS file → Open with → choose your spreadsheet app (or open the app first and use File → Open).
- If you want a new spreadsheet based on the template, use the app’s template workflow (open the template, then save the new document as .ODS).
Common issues
The .OTS file won’t open or shows an unknown format error
This usually happens when your spreadsheet app doesn’t support OpenDocument templates or the file association points to the wrong program.
- Open the file from inside an ODF-compatible spreadsheet app (for example, LibreOffice Calc) using File → Open.
- On desktop systems, use “Open with” and choose the spreadsheet app explicitly, then set it as the default for .ots if desired.
It opens, but I can’t edit (or edits don’t behave as expected)
Some workflows treat templates as a starting point and expect you to create a new document from them. Editing the template directly can be confusing or may overwrite the template you intended to reuse.
- Create a new document from the template (or open it and immediately “Save As” a working spreadsheet, commonly .ODS).
- Keep the original .OTS unchanged and store it separately as your master template.
The file looks corrupted or content is missing
The download/copy may be incomplete, or the file may have been produced by software that wrote a non-compliant template.
- Re-download or re-copy the file and try opening again in an ODF-compatible app (for example, LibreOffice Calc).
- If it still fails, ask the sender to re-export/recreate the template as a standard ODF spreadsheet template (.OTS).
Security note
.OTS files are documents (not executables), but they can still be used to deliver unexpected content; only open templates from sources you trust.