Which files can I use?

XLSX workbooks that embed a PNG preview image (most files saved with a "save preview picture" or similar option), up to 40 MB.

What does the tool return?

The embedded preview image as a PNG file. It is exactly the thumbnail stored inside the workbook.

What if my workbook has no embedded preview?

The conversion lets you know it could not find a preview image, instead of inventing one.

Extract the embedded thumbnail from a spreadsheet

Spreadsheet apps can store a small preview picture inside an XLSX workbook. This page pulls that embedded thumbnail out and gives it to you as a standalone PNG.

How to extract the thumbnail

Upload an XLSX file (up to 40 MB).
Press Convert file.
Download the PNG preview that was embedded in the workbook.

Why it is useful

See the thumbnail without opening the workbook in a spreadsheet app.
Reuse the preview image in catalogs, dashboards, or documentation.
Check what a workbook looks like at a glance.

Limits

XLSX workbooks up to 40 MB.
Only the embedded PNG preview is extracted — cell data is left untouched.
If the workbook does not contain an embedded preview image, no output is produced.