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Free Online XLS Converter — Convert Legacy Excel Files

Convert legacy XLS (Excel 97-2003) spreadsheets to modern XLSX, PDF, CSV, and more.

Drop XLS files here
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Max file size 10MB. Sign up for more.

How to Convert XLS Files Online — Free & Instant

Convert legacy Excel 97-2003 XLS spreadsheets to modern formats without needing older versions of Office.

Upload Your XLS Spreadsheet

Drag and drop XLS files created in Excel 97-2003 or earlier. The converter reads the binary BIFF format including cell values, formulas, formatting, charts, and multiple worksheets.

Select a Modern Format

Choose XLSX to upgrade to the modern Excel format with smaller file sizes, CSV for data extraction and database imports, PDF for printable output, or ODS for LibreOffice Calc compatibility.

Download Converted Spreadsheet

Download your spreadsheet in a modern format that every current application supports. XLS to XLSX conversion preserves all data, formulas, and formatting while reducing file size.

Why Convert XLS Spreadsheets?

Upgrade to Modern XLSX

XLS is a legacy binary format from Excel 97-2003. Convert to XLSX for smaller file sizes, better formula support, more rows and columns, and compatibility with current Excel features.

Extract Data as CSV

Convert XLS to CSV for importing data into databases, analytics tools, and modern applications. CSV eliminates binary format complexity and works with every data processing system.

Fix Compatibility Issues

Legacy XLS files may show formatting errors in modern Excel, Google Sheets, or Numbers. Converting to XLSX resolves rendering issues and ensures data displays correctly.

Create Printable Reports

Convert XLS to PDF for clean, formatted printouts of spreadsheet data. PDF preserves column widths, cell borders, and number formatting across all printers.

Open in Free Software

Convert XLS to ODS for editing in LibreOffice Calc without a Microsoft Office license. ODS preserves cell data, formulas, and basic formatting in an open-standard format.

Archive Legacy Spreadsheets

The XLS binary BIFF format risks becoming unreadable. Convert to XLSX or CSV to future-proof your spreadsheet data for long-term access and compliance.

No Software Required

Convert XLS documents directly in your browser — no desktop apps, no plugins. No watermarks added, formatting preserved, and files are deleted from our servers within 24 hours.

About the XLS Format

XLS is the legacy spreadsheet format used by Microsoft Excel from version 97 through 2003. It stores data in the Binary Interchange File Format (BIFF), a proprietary binary structure that encodes cell values, formulas, formatting, charts, and macros. XLS files are limited to 65,536 rows and 256 columns per worksheet compared to the million-plus rows in modern XLSX.

Despite being superseded by XLSX, XLS files remain common in legacy enterprise systems, government agencies, and archived business data. The format supports VBA macros, embedded objects, and multiple worksheets. XLS files can be opened in modern Excel, Google Sheets, LibreOffice Calc, and most spreadsheet applications, though converting to XLSX is recommended for better performance, larger data capacity, and improved security.

XLS Converter FAQ

Quick answers about output formats, compatibility, quality trade-offs, and the best workflows for XLS files.

What can I convert XLS files to?

You can convert XLS to PDF, DOCX, TXT, RTF, and HTML, and more. XLS is the Microsoft Excel format; choose the target that matches where you'll use the document — each conversion has its own dedicated tool with quality settings tuned for that pair.

How do I convert XLS files online?

Pick the XLS conversion you need above, upload your file, and click Convert. It's processed in seconds and downloads instantly — free, no watermark, and no account required. Batch upload is supported.

Is the XLS converter free?

Yes. Converting XLS files is completely free with no watermark and no sign-up. Paid plans only raise file-size limits and batch sizes for heavier workloads.

Will converting my XLS file reduce quality?

It depends on the target format. Converting XLS to a lossless format keeps every detail, while lossy targets use high-quality defaults so the result stays faithful to the original. You never lose quality that wasn't already in the source.

Are my XLS files kept private?

Yes. Uploads use an encrypted HTTPS connection, conversion runs on an isolated worker, and both your file and the result are deleted automatically within a short window — nothing is stored, shared, or used for training.

Is there a file size limit for converting XLS?

The free plan supports files up to 50 MB, which covers most XLS files. Starter raises the limit to 100 MB, Plus to 1 GB, and Pro to 5 GB for larger files.

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