Convert Files to XLS, XLSX & ODS Online — Free Spreadsheet Converter
This free online converter transforms a wide range of input files into Microsoft Excel (XLS, XLSX) or OpenDocument Spreadsheet (ODS) format — no software installation needed, just upload your file and download the result.
What are XLS, XLSX, and ODS?
XLS is the legacy Microsoft Excel binary format introduced in the 1980s and used through Excel 2003. XLSX is the modern Office Open XML format introduced with Excel 2007; it is smaller, more reliable, and the default format in all current versions of Excel and compatible suites such as Google Sheets and LibreOffice Calc. ODS (OpenDocument Spreadsheet) is the ISO-standardised open format used natively by LibreOffice Calc, Apache OpenOffice, and a growing number of applications — making it a good choice when long-term, vendor-neutral compatibility matters.
Why convert to a spreadsheet format?
Spreadsheet formats unlock structured data editing, formula calculations, sorting, filtering, and charting that plain-text or document formats cannot provide. Common reasons to convert include:
- Importing CSV or tabular data exports from databases, CRMs, or reporting tools into a fully editable Excel workbook.
- Opening a file from one office suite in another without losing table structure or formatting.
- Archiving data in an open standard (ODS) to avoid future vendor lock-in.
- Sharing a workbook with colleagues who use different versions of Excel or LibreOffice.
Supported input formats
The converter accepts a broad range of document and data formats as input, including common spreadsheet types (XLS, XLSX, ODS, CSV), word-processing documents that contain tables, and other structured document formats. The exact list of accepted input types is shown in the upload form above. Output can be set to XLS, XLSX, or ODS depending on your target application.
Frequently asked questions
Is this spreadsheet converter free to use?
Yes, converting files to XLS, XLSX, or ODS is completely free. No account or subscription is required, though registered users can opt in to receive an email notification when their conversion is ready.
What is the difference between XLS and XLSX?
XLS is the older Excel binary format compatible with Excel 97–2003. XLSX is the newer Office Open XML format used by Excel 2007 and later; it produces smaller files, supports more rows and columns, and is generally more stable. Unless you need compatibility with very old software, XLSX is the recommended choice.
Can I open an XLSX file in LibreOffice or Google Sheets?
Yes. Both LibreOffice Calc and Google Sheets support XLSX natively. If you prefer a fully open format, convert to ODS instead, which is the native format of LibreOffice and other open-source office suites.
What happens to my uploaded file after conversion?
Uploaded files are processed on the server to perform the conversion and are then deleted automatically. They are not stored permanently or shared with third parties.
Will formulas and formatting be preserved during conversion?
Conversion accuracy depends on the source format. Tabular data, basic cell formatting, and simple structures are generally preserved well. Complex formulas, macros, or pivot tables may not survive conversion from non-spreadsheet source formats.