Convert Excel Spreadsheet (Legacy) files to Excel Spreadsheet format instantly. Free, fast, and private — no signup required.
Supports XLS and more
Files are processed locally in your browser. Nothing is uploaded to a server.
The XLS to XLSX converter transforms Excel Spreadsheet (Legacy) files into Excel Spreadsheet format. Upload your .xls file and get a .xlsx file instantly — no software to install, no account to create.
XLS: Legacy Excel format. XLSX: Modern Excel spreadsheet format. Converting from XLS to XLSX is useful when you need the specific advantages of the XLSX format — whether that's compatibility, file size, quality, or feature support.
The converter processes your XLS document and transforms it into XLSX format. Text content, basic formatting, and structure are preserved during conversion. Complex layouts may need minor adjustment in the output file.
Getting Started
Drag and drop your file into the converter, or click to browse. Supports XLS and more.
Configure output settings like quality, size, and format options. Defaults work well for most use cases.
Click "Convert" and your XLSX file is ready in seconds. Free, unlimited, no account required.
Sharing documents across different software platforms. Preparing files for submission, printing, or archiving. Converting between Microsoft, Apple, and open-source format ecosystems.
| Attribute | XLS | XLSX |
|---|---|---|
| Format type | Excel Spreadsheet (Legacy) | Excel Spreadsheet |
| MIME type | application/vnd.ms-excel | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| Typical use | Legacy Excel format. | Modern Excel spreadsheet format. |
| Keep as source when | the file must stay editable in its native application | the file must look identical on every device and printer |
In short: keep XLS when you are still working with the file, and use XLSX when you are sharing, publishing, or opening it on devices that do not support XLS.
FAQ
Upload your .xls file to the converter, and it produces a .xlsx file automatically. Click Download to save the result. The entire process runs in your browser — nothing is uploaded to a server.
Yes. Completely free with no signup, no watermarks, and no file limits. You can convert as many files as you need.
Yes. Every conversion runs locally in your browser. Your file is never uploaded to a server, never stored, and never seen by anyone but you. This makes the XLS to XLSX converter safe for contracts, ID scans, and other sensitive documents.
No fixed limits. Because files are processed on your own device rather than a server, the practical limit depends on your device's memory, not an upload quota.
Basic text formatting, paragraphs, and structure are preserved. Complex layouts, custom fonts, and advanced formatting may need minor adjustment after conversion.
Yes. Upload multiple .xls files and they all convert to .xlsx format. Download them individually or as a batch.
XLS is a Excel Spreadsheet (Legacy) file — Legacy Excel format. XLSX is a Excel Spreadsheet file — Modern Excel spreadsheet format. The right choice depends on where the file needs to open and whether you are still editing it.
Yes. The converter runs in any modern browser — Android, iPhone, iPad, Windows, macOS, and Linux. No app installation is needed because all processing happens on your own device.
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