Format comparison
XLS vs ODT
How do XLS and ODTcompare? Here's everything you need to know to choose the right format — and how to convert between them.
.xls
Full guide →Microsoft Excel Spreadsheet (Legacy)
XLS is the legacy binary format used by Microsoft Excel before 2007. While superseded by XLSX, many existing spreadsheets and enterprise systems still use this format.
.odt
Full guide →Open Document Text
ODT is an open-standard document format used by LibreOffice, OpenOffice, and Google Docs. It's the free, vendor-neutral alternative to DOCX for word processing.
| Specification | XLS | ODT |
|---|---|---|
| Full name | Microsoft Excel Spreadsheet (Legacy) | Open Document Text |
| Extension | .xls | .odt |
| MIME type | application/vnd.ms-excel | application/vnd.oasis.opendocument.text |
| Category | Document | Document |
| Developer | Microsoft | OASIS (Organization for the Advancement of Structured Information Standards) |
| Year introduced | 1987 | 2005 |
XLS advantages
- Compatible with older Excel versions
- Widely recognized format
- Supported by all major spreadsheet apps
- Large installed base
XLS limitations
- Limited to 65,536 rows and 256 columns
- Larger file sizes than XLSX
- Binary format — harder to recover
- Missing modern Excel features
ODT advantages
- Open standard — no vendor lock-in
- Free to use with no licensing fees
- Supported by LibreOffice, Google Docs, and more
- Long-term archival format (ISO standard)
ODT limitations
- Less common in business environments
- Formatting differences with Microsoft Office
- Fewer advanced features than DOCX
- Limited template ecosystem
Which should you use?
XLS and ODT serve different purposes. XLS is ideal for legacy spreadsheet compatibility, while ODT excels at government and public sector documents.
Best uses for XLS
Legacy spreadsheet compatibility
Older enterprise systems
Historical data archives
Backward-compatible exports
Best uses for ODT
Government and public sector documents
Academic and educational use
Open-source workflows
Long-term document archival
Convert between XLS and ODT
Need to switch formats? Convert for free with SquishConvert.