PDF vs XLS
How do PDF and XLScompare? Here's everything you need to know to choose the right format — and how to convert between them.
Portable Document Format
PDF is the universal standard for sharing documents. It preserves formatting, fonts, and layout across all devices and operating systems. From contracts to resumes, PDF is the format the world relies on.
.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 While superseded by XLSX, many existing spreadsheets and enterprise systems still use this format.
| Specification | XLS | |
|---|---|---|
| Full name | Portable Document Format | Microsoft Excel Spreadsheet (Legacy) |
| Extension | .xls | |
| MIME type | application/pdf | application/vnd.ms-excel |
| Category | Document | Document |
| Developer | Adobe Systems | Microsoft |
| Year introduced | 1993 | 1987 |
PDF advantages
- Consistent display on all devices
- Supports digital signatures and forms
- Compact file sizes with good compression
- Industry standard for official documents
PDF limitations
- Difficult to edit without specialized software
- Not ideal for responsive or reflowable content
- Can be large with embedded fonts and images
- Accessibility can be poor if not properly tagged
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
Which should you use?
PDF and XLS serve different purposes. PDF is ideal for business documents and contracts, while XLS excels at legacy spreadsheet compatibility.
Best uses for PDF
Best uses for XLS
Convert between PDF and XLS
Need to switch formats? Convert for free with SquishConvert.