How do I convert an XLS file to XLSX?

Click 'Choose File' to upload your .xls, then select XLSX from the drop-down. The converter rewrites the binary spreadsheet into an XML-based XLSX workbook, preserving all cells, formulas, and formatting. Download the new file instantly.

Why should I convert XLS to XLSX?

XLS is Microsoft's legacy binary format used before Excel 2007. XLSX uses ZIP-compressed XML, which reduces file size by up to 75% and enables modern features like larger grids and better data recovery. It's the default standard for Excel, LibreOffice, and Google Sheets.

What happens to macros, formulas, and charts during XLS to XLSX conversion?

Formulas, charts, images, and cell formatting are fully preserved during conversion. However, XLSX is a macro-free format, so VBA macros from the original XLS file are stripped to maintain security and compatibility. If you need macros, export to XLSM instead.

Is XLS-TO-XLSX free to use?

Yes, XLS-TO-XLSX on LetsConvert is 100% free with no registration or hidden fees required.

Are my uploaded files safe and secure?

Yes! File privacy and security are guaranteed. Basic conversions run locally in your browser. Files sent for server processing are automatically deleted within 1 hour.

Does this converter work on mobile phones and tablets?

Yes! XLS-TO-XLSX works seamlessly across iPhone, Android, iPad, Mac, Windows, and Linux browsers without installing any app.

Is there any software installation required?

No software or browser extension installation is needed. All conversions are performed directly online.

XLS-TO-XLSX

Convert binary XLS to modern XLSX XML online. Reduces file size, unlocks Excel 2007+ features, and preserves formulas, formatting, and macros.

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📄XLSsource

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📝XLSXtarget

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Select your XLS file to convert

or drop your file here. Supports up to 50MB · Private & secure

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XLS

XLS File Format

Source Format

XLS is a standardized digital file format supported by LetsConvert. Convert XLS files securely, privately, and instantly online with zero software installation, bank-grade encryption, and automatic 60-minute file purging.

Category: Data & Media File

MIME Type: application/xls

Developer: Standard Organization

Best For: Converting and managing XLS files across devices and applications.

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XLSX

XLSX File Format

Target Output

XLSX is a standardized digital file format supported by LetsConvert. Convert XLSX files securely, privately, and instantly online with zero software installation, bank-grade encryption, and automatic 60-minute file purging.

Category: Data & Media File

MIME Type: application/xlsx

Developer: Standard Organization

Best For: Converting and managing XLSX files across devices and applications.

💡 Technical Guide & Conversion Insights

Why Convert XLS to XLSX?

Converting from XLS (XLS File Format) to XLSX (XLSX File Format) is essential when you need enhanced compatibility, reduced file size, or specific feature support. While XLS is ideal for Converting and managing XLS files across devices and applications., XLSX offers superior advantages for Converting and managing XLSX files across devices and applications.. Our secure online conversion engine ensures that all your XLS file attributes, geometry, quality, and metadata are seamlessly preserved during the transformation into XLSX.

● XLS Key Advantages:

✓Standard format compatibility
✓Fast online conversion processing
✓Zero software install required

● XLSX Key Advantages:

★Standard format compatibility
★Fast online conversion processing
★Zero software install required

XLS vs XLSX Comparison Table

Detailed technical differences and capabilities between XLS File Format and XLSX File Format.

Feature / Attribute	XLS	XLSX
Primary Format Name	XLS File Format	XLSX File Format
Primary File Category	Data & Media File	Data & Media File
Standard MIME Type	application/xls	application/xlsx
Core Developer / Standard	Standard Organization	Standard Organization
Optimal Use Case	Converting and managing XLS files across devices and applications.	Converting and managing XLSX files across devices and applications.

❓ Common Questions

Frequently Asked Questions (XLS to XLSX)

Everything you need to know about converting XLS to XLSX with LetsConvert.

To convert your XLS file to XLSX, upload your file by dragging and dropping it into the upload box or selecting it from your device. Adjust any optional quality or dimension settings, then click 'Convert'. Your converted XLSX file will be ready for instant high-speed download within seconds.

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100% Secure & Automatic File Purging

Your XLS files are encrypted with 256-bit SSL and permanently deleted from our servers within 60 minutes.

● Zero File Storage

How to Convert XLS-TO-XLSX

Select or drop your Xls file.

Initiate the XLSX conversion process.

Download your converted XLSX file.

⚡ Related Converters

XLS-TO-XLSX

Select your XLS file to convert

XLS

XLSX

Why Convert XLS to XLSX?

● XLS Key Advantages:

● XLSX Key Advantages:

XLS vs XLSX Comparison Table

Frequently Asked Questions (XLS to XLSX)

100% Secure & Automatic File Purging

How to Convert XLS-TO-XLSX

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