twineconvert

free · in-browser · no upload

XLSX to ODS
Converter

Drop your XLSX file. We'll convert it to ODS right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .xlsx, .xls

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a XLSX from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your ODS the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Formats involved

About XLSX and ODS

XLSX, Microsoft Excel Spreadsheet

XLSX is the spreadsheet format Excel has used since 2007, like DOCX, it's a zip containing XML for cells, formulas, formatting, and embedded objects. Replaces the older binary .xls format. Read and written by Excel, Google Sheets, Apple Numbers, and LibreOffice Calc, with high fidelity for standard cell data and reasonable fidelity for complex formulas and pivot tables.

How to open

Microsoft Excel, Google Sheets, Apple Numbers, LibreOffice Calc. CSV is a more portable format if you only need the raw cell values.

Full XLSX format guide →
ODS, OpenDocument Spreadsheet

ODS is the OpenDocument format spreadsheet, used by LibreOffice Calc, Apache OpenOffice Calc, and Collabora Online. ZIP-packaged XML structure standardized by ISO/IEC 26300. The free/open-source counterpart to Microsoft's XLSX. Excel reads ODS but with feature loss on complex formulas; LibreOffice reads XLSX with similar caveats.

How to open

LibreOffice Calc (free, every desktop OS) is the native editor. Microsoft Excel opens ODS but pins it as 'OpenDocument' with a downgraded ribbon. Google Sheets imports ODS via File → Import.

Full ODS format guide →

Related tools

Convert other files to ODS

Convert your XLSX to other formats

FAQ

Common questions

Is this XLSX → ODS converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert XLSX to ODS?

Spreadsheets with formulas, formatting, multiple sheets. Spreadsheet exchange in the LibreOffice/OpenOffice ecosystem. The most common reason to convert is compatibility, ODS works in places where XLSX doesn't, or vice versa.

How do I open a XLSX file in the first place?

Microsoft Excel, Google Sheets, Apple Numbers, LibreOffice Calc. CSV is a more portable format if you only need the raw cell values.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.