Documents
What is a XLS file?
XLS is the file format used by older spreadsheet software to store spreadsheets, data, and formulas in a single binary file. It was the standard spreadsheet format for years before being replaced by XLSX. Most current software can still open it, but a few modern features and formulas don't translate cleanly from the newer format.
- Extension
- .xls
- Type
- Documents
- Typically
- Old Excel files
- Metadata
- Carries EXIF
Why XLS exists
XLS is a binary format, meaning the data is packed in a way that's efficient for the program to read but not something you can peek into with a text editor. It was the default spreadsheet format for roughly two decades before being replaced around 2007 by XLSX, a newer format built on a different structure.
In plain terms, an XLS file holds everything a spreadsheet needs: the grid of cells, the numbers and text in them, formulas, formatting like colors and column widths, and sometimes charts. All of that gets bundled into one file that spreadsheet software can read back and rebuild exactly as it was saved.
People mostly run into XLS today when they open an old file, one downloaded from a government or business site, or one exported from an older system that never moved to the newer format. Modern spreadsheet apps still open XLS, but converting it to XLSX is common because the newer format is smaller, handles bigger sheets, and works better with current tools.
You'll also see XLS come up when someone needs the data in a different shape entirely, like pulling it into a CSV for a script or database import.
The trade-offs
Strengths
- Opens in nearly all spreadsheet software, old and new
- Keeps formulas, formatting, and multiple sheets intact
- Still common in exports from older business and government systems
Watch-outs
- Larger file size than the newer XLSX format
- Caps out at fewer rows and columns than modern spreadsheets support
- Some newer formulas and formatting options don't carry over cleanly
A note on privacy
An XLS file can carry more than just the cells you see. It may include author names, edit history, and hidden sheets or cached data left over from earlier versions of the file. Uploading it to an online converter sends all of that to someone else's server; converting it on your own computer keeps the spreadsheet, and whatever is buried in it, on your machine.
Convert a XLS file
Questions
How do I open an XLS file?
Any current spreadsheet application on Mac or Windows will open it directly, no conversion needed. If you don't have spreadsheet software installed, you'll need to convert it to something more widely readable, like CSV.
Is XLS the same as XLSX?
No. XLS is the older binary format and XLSX is its replacement, built on a different structure that's smaller and supports larger sheets. Most software today opens both, but new files are usually saved as XLSX by default.
Why do I still see XLS files?
Older systems, archived downloads, and some business or government tools still export data in XLS. It also shows up when a file was saved years ago and never resaved in a newer format.
Can I convert XLS without uploading it?
Yes. A desktop app like Morphjet converts XLS to XLSX, CSV, or other formats on your own computer, so the spreadsheet and any hidden data in it never leave your machine.
Will converting XLS to XLSX lose anything?
Usually not. Cell data, formulas, and formatting carry over cleanly in most cases. It's worth a quick check on complex sheets with macros or unusual formatting, since those are the parts most likely to shift.
Morphjet opens and converts XLS, one of 2,748 conversions it runs on your own computer. Available now.
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