Excel · .xls
Excel · .xlsExcel: “The file format and extension don't match”
The file format and extension of 'Budget 2026.xls' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?
The file is named .xls, but what is inside is not the old Excel format. Often it is harmless: many systems export HTML or text tables with a .xls name. Sometimes the old format is there but damaged.
Fix it now, free
Drop the file here. We show you what is wrong and the repaired file before you download it. Nothing is stored.
.xlsx .docx .pptx .xls .doc .ppt, up to 50 MB
Why it happens
- A website, bank or business system exported a report as an HTML or tab-separated table and named it .xls.
- A real .xls whose header was damaged, so Excel no longer recognises it.
- A file renamed by hand to the wrong extension.
Try these first, they're free
- 1If you trust the sender, click Yes: an exported table usually opens fine. Then save it with File › Save As as a .xlsx.
- 2If it opens as garbled symbols, the file is a real .xls that is damaged, so do not save over it.
How we fix it
We tell which it is from the contents. A damaged .xls has its header and internal filesystem rebuilt, is converted, and comes back as a .xlsx that opens with no warning.
On 384 damaged Office files, we recovered 81% of the content; Office's own repair recovered 53%. See the benchmark.