How the free online spreadsheet converter works
Spreadsheet formats differ more in structure than in content. XLSX, XLS and ODS are workbooks: several sheets, formulas and formatting in one file. CSV is a single table of plain text that every program can read. Converting between workbooks keeps every sheet and formula; converting to CSV keeps the first sheet as values only, which is exactly what databases and import tools want.
The converter uses SheetJS, the open-source library behind many spreadsheet tools, running in your browser. It rebuilds the workbook from its cells, so values and formulas come across faithfully, while charts, images, pivot tables and cell styling such as colours are not carried over.
Which spreadsheet format should you use?
XLSX is the default for anything you will keep working on: it holds several sheets, formulas and formatting, and opens in Excel, Google Sheets, Numbers and LibreOffice. XLS is the older binary Excel format, worth choosing only when a legacy system insists on it, and limited to 65,536 rows per sheet.
ODS is the open standard spreadsheet format used by LibreOffice and required by some public bodies. It holds the same things as XLSX. CSV is different in kind: a single table of plain text with no formulas or formatting, which is exactly why every database, CRM, email platform and analytics tool imports it.
A common workflow is to keep the master as XLSX or ODS and export CSV whenever data has to go into another system. Converting CSV back to a workbook gives you a sheet you can format, sort and add formulas to.
Common spreadsheet conversions and why people need them
The most common tasks are simple ones. Exporting a customer list from a CRM gives a CSV that is easier to read, sort and filter as XLSX. Uploading contacts to an email platform or products to a shop needs the reverse: a CSV with one row per record. Accounting and government portals sometimes still ask for XLS, and some public bodies require ODS, the open standard.
Each of those is one conversion here. The workbook is read by SheetJS, a widely used open-source spreadsheet library, running inside this tab, so payroll sheets, price lists and customer data are never uploaded. Formulas are carried between XLSX, XLS and ODS, and CSV output is UTF-8 so names in every alphabet survive.
If you work with the same export every week, keep a copy of the converted workbook as a template: format it once, then paste each new export into it.
Spreadsheet formats compared
| Format | Compression | Best for |
|---|---|---|
| CSV | Lossless | data exports, imports into databases and exchanging tables between programs |
| ET | Lossless | spreadsheets made in WPS Office, widely used in China |
| ODS | Lossless | LibreOffice and OpenOffice users and public-sector documents |
| XLS | Lossless | older Excel files and systems that still export the legacy format |
| XLSM | Lossless | workbooks that automate reports, imports and calculations with macros |
| XLSX | Lossless | business spreadsheets, reports and anything shared with Excel users |
Tips for converting spreadsheet files
- Move the sheet you need to the first position before converting to CSV, because CSV keeps one sheet.
- Check dates after importing a CSV; spreadsheets store dates as numbers and a format may need applying.
- Remove empty rows and unused sheets first to keep the result small.
- Keep the original workbook; charts and styling are not carried over.
Is it safe to convert spreadsheet files online?
With most online tools, "online" means your file is uploaded to a company's server, processed there and kept for a while before it is deleted. Here it is not. The page downloads the converter code to your browser, and your file is read and processed inside the tab on your own device. It is never sent to TapToConvert or anyone else.
You can check this yourself: once the page and, for audio and video, the converter engine have loaded, turn off Wi-Fi and the tool still works. That also means there is no queue, no daily limit and no size cap set by a server. The only limit is the memory your browser gives a single tab.
Spreadsheet Converter FAQ
Will my formulas survive?
Between XLSX, XLS and ODS, yes: formulas are carried over. CSV cannot hold formulas, so their last calculated values are saved instead.
Are charts and colours kept?
No. The converter rebuilds the workbook from its cells, so charts, images, pivot tables and cell styling are not carried over.
Why does my CSV look wrong in Excel?
Older Excel versions assume a local character set. Use Data, From Text/CSV and choose UTF-8 to open it correctly.
Is there a row limit?
XLSX and ODS handle over a million rows; XLS stops at 65,536 per sheet. Very large files are limited by your device memory.
Is the spreadsheet converter free?
Yes, with no sign-up, no watermark and no limit on the number of files. It is supported by advertising, and because files are converted on your device there is no server cost per conversion.
Does the spreadsheet converter work on phones?
Yes. It works in Safari on iPhone and iPad and in Chrome on Android. Converted files are saved to your Downloads folder.