XLS to XLSX Converter

Convert your XLS files to XLSX in seconds — free and online.
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Select or drag & drop files to begin.

How to convert XLS to XLSX?

Just three simple steps — no downloads, no hassle.
Click the “Choose files” button and upload your XLS file.

You can drag and drop it too — we’re flexible!

Choose “XLSX” as the output format, then click “Convert”.

We’ll take care of the rest — it only takes a few seconds.

All done! Your file is now in XLSX format.

Just download it and enjoy. Easy, right?

At a glance: XLS to XLSX

🔁 Conversion: XLS to XLSX ⏱ Average conversion time: 20 seconds 💳 Cost: Free 📂 Category: Spreadsheets ✳️ Extensions: .xls → .xlsx 📏 Max file size: 75 MB 👩‍💻 Works on: Windows, Linux, macOS, iOS, Android

About XLS

XLS is the original spreadsheet file format for Microsoft Excel (up to version 2003). It stores data in rows and columns, with support for formulas, charts, and macros. XLS files have been largely replaced by the newer XLSX format.

About XLSX

XLSX is the modern Excel spreadsheet format introduced with Microsoft Office 2007. It uses ZIP compression and an XML-based structure, resulting in smaller files and better compatibility. XLSX supports advanced spreadsheet features and is widely used in business and data analysis.

Why Convert XLS to XLSX with MiConv?

Because it's quick, easy, and made for people like you.

No software needed

Convert your .xls files to .xlsx right in your browser — no downloads, no installs. Everything happens securely in the cloud.

Your files stay private

We never store your files permanently. Only you can access them, and they’re automatically deleted from our servers within 2 hours.

Fast, free, and effortless

Turn your XLS files into XLSX in just a couple of clicks. No registration, no limits — and it’s 100% free.

More XLS conversions you can try

Explore other formats you can turn your XLS files into — it's easy!

XLS to XLSX Converter Quality Rating

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