In Excel: use File ▸ Open ▸ Browse, select the file, then click the arrow beside the Open button and choose Open and Repair — take Repair first, and Extract Data only if that fails.
On this page7
Copy the damaged file first and work on the copy — several of these steps overwrite it.
File ▸ Open ▸ Browse ▸ select the file ▸ click the arrow beside Open ▸ Open and Repair ▸ Repair.
If Repair fails, run it again and choose Extract Data, then pick Convert to Values when asked.
Still nothing: try opening it in Google Sheets, LibreOffice Calc or Numbers — a different parser sometimes succeeds.
For .xlsx only: copy the file, rename the copy to .zip, extract it, and look in xl/worksheets and xl/media for the sheet XML and images.
Check File ▸ Info ▸ Manage Workbook ▸ Recover Unsaved Workbooks and the AutoRecover folder for an earlier version.
Save whatever opens under a new name before doing anything else.
What this does
Excel's built-in Open and Repair is the first and usually the only tool worth reaching for. It offers two passes: Repair rebuilds the workbook structure and keeps formulas where it can, and Extract Data pulls values (optionally converting formulas to their last calculated results) out of a file too damaged to rebuild. When both fail there are two more routes that cost nothing: opening the workbook in a different application (Google Sheets, LibreOffice and Numbers each have their own parser and sometimes read a file Excel rejects), and — for .xlsx files, which are ZIP archives — renaming a copy to .zip and extracting it to recover the embedded worksheet XML and any images. "The file format is not valid" is usually not corruption at all but a mismatched extension: a .xls file renamed .xlsx, or an HTML export saved with a spreadsheet extension. Most people learn this as a sequence of clicks and forget it by next week; learning it as a pattern instead is what lets you apply it to the next, slightly different version of the problem without starting from scratch. That is the difference this page is trying to make. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “excel cannot open the file because the file format”. Start on a copy or a tiny sample, keep the affected cells visible, and compare the result with the tool above before you touch the real workbook. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. The point is a data step that keeps your analysis trustworthy, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
A 40 MB workbook that closed during a save now refuses to open. File ▸ Open ▸ Browse ▸ select it ▸ arrow beside Open ▸ Open and Repair ▸ Repair. Excel reports it removed a damaged chart and opens the rest with formulas intact. Save immediately under a NEW name, so the original stays available if the repair turned out to be partial. A damaged workbook is recoverable far more often than it looks, and the free routes work often enough that paying for a recovery tool should be the last step rather than the first. A practical tip: try it on a copy of the sheet or a handful of sample rows first and check the result before you apply it to the real data. That one habit catches almost every surprise while it is still cheap to reverse.
In Google Sheets
This is a command rather than a formula, so there is no syntax to carry over. Google Sheets arranges its commands in menus across the top instead of a ribbon, names some of them differently and does not have every Excel command — look for the equivalent in the Sheets menus or its help before assuming the steps match. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. If you take one thing from this page on “excel cannot open the file because the file format”, make it the order of checks rather than the individual clicks: confirm what is selected, apply the step, and look at the result before moving on. That small routine is what keeps Excel work predictable when the same task comes back in a slightly different workbook.
Common mistakes
- Repairing in place, so a partial repair destroys the only copy you had.
- Paying for a recovery tool before trying Open and Repair, another application, and the ZIP route — all free.
- Assuming "file format is not valid" means corruption when the extension simply does not match the real format.
- Ignoring the cause: a workbook that corrupts repeatedly usually points at a flaky network share, an add-in, or saving over SMB with a dropping connection.
- Overlooking AutoRecover, which often holds a version only minutes older than the damaged file.
Frequently asked questions
How do I repair a corrupted Excel file?
File ▸ Open ▸ Browse, select the file, click the arrow beside Open, choose Open and Repair, and take Repair before Extract Data.
Can I recover data if Repair fails?
Run Open and Repair again and choose Extract Data, which recovers values and can convert formulas to their last results. Failing that, open the file in Google Sheets or LibreOffice.
What does "the file format is not valid" mean?
Usually that the extension does not match the contents — for example a .xls or an HTML export renamed to .xlsx. Rename it back to the true format and reopen.
Why does Excel keep crashing on one file?
Common causes are a broken add-in (start Excel in Safe Mode), an enormous used range, volatile formulas across hundreds of thousands of rows, or saving directly to an unreliable network share.
Are online Excel repair services safe?
They require uploading your data to a third party. Try Open and Repair, another spreadsheet application and the .zip extraction route first — they are free and keep the file on your machine.
Other ways people ask this
People reach this page typing “excel cannot open because the file format”, “excel file cannot open because file format”, “excel cannot open file because the file format” and “excel cannot open file because the format”, among other phrasings; whichever wording you used, the fix above is the one you want.
Why do people search for this in so many different ways?
Because the same task has many names. “excel cannot open because the file format”, “excel file cannot open because file format”, “excel cannot open file because the file format” all point at the one operation explained on this page, which is why they all lead here.