Can it read old .xls files?

No — .xls is a different, binary format. Open the file in Excel or LibreOffice, save it as .xlsx, and convert that. The tool tells you this clearly instead of failing silently.

What happens to formulas?

You get the result that was stored in the file when it was last saved — the cached calculated value. The formula text itself is not exported and nothing is recalculated.

How are dates handled?

Cells with date or time number formats are converted from Excel's serial numbers to readable ISO form (like 2026-08-22 or 14:30:00), rounded to the second. Plain numbers without a date format stay numbers.

Is my file uploaded to a server?

No. The workbook is unpacked and parsed entirely in your browser — your data never leaves your device.

Convert Excel (XLSX) to CSV

Select an .xlsx workbook, pick a sheet if there's more than one, and get its contents as comma-separated CSV — previewed on screen, ready to copy or download. Shared strings, inline text, booleans and dates are all resolved to what the cells actually say. Nothing is uploaded to Filesvo.

or drag and drop an .xlsx file here

Processed on your device — files are never uploaded to Filesvo.

How to use Filesvo

Select or drop an .xlsx file.
Click Convert to CSV, then pick the sheet if the workbook has several.
Copy the result or download the .csv file.

What the cells become

Text cells come out as text, numeric cells as plain numbers, and booleans as TRUE or FALSE. Cells styled with a date or time format are converted from Excel's internal serial numbers into readable ISO dates — 2026-08-22, or 2026-08-22 14:30:00 when there's a time part — honoring both the standard and the legacy Mac (1904) date systems.

Formula cells export the last value Excel calculated and saved in the file — the formula itself is not re-evaluated. Fields containing commas, quotes or line breaks are quoted per the CSV standard, so the output re-imports cleanly anywhere.

Transparency handling

Formulas export their cached calculated values, not the formulas. Password-protected workbooks and the older binary .xls format are not supported — re-save as .xlsx first.

Private by design

Your files are processed directly in your browser using open-source engines that run in your browser and are not uploaded to Filesvo. Nothing is stored on our servers, because nothing ever reaches them.

Frequently asked questions

Can it read old .xls files?: No — .xls is a different, binary format. Open the file in Excel or LibreOffice, save it as .xlsx, and convert that. The tool tells you this clearly instead of failing silently.
What happens to formulas?: You get the result that was stored in the file when it was last saved — the cached calculated value. The formula text itself is not exported and nothing is recalculated.
How are dates handled?: Cells with date or time number formats are converted from Excel's serial numbers to readable ISO form (like 2026-08-22 or 14:30:00), rounded to the second. Plain numbers without a date format stay numbers.
Is my file uploaded to a server?: No. The workbook is unpacked and parsed entirely in your browser — your data never leaves your device.

CSV to Excel Converter

Turn a CSV file into a real Excel .xlsx workbook — entirely in your browser.

CSV to JSON Converter

Turn CSV data into JSON — paste or upload, pick the delimiter, get an array of objects. Runs entirely in your browser.

JSON Formatter & Validator

Pretty-print, validate or minify JSON with clear error messages — entirely in your browser.