Documents

SXC → XLSX

Learn about the formats: What is XLSX?

At a glance

ConvertX.am converts SXC files to XLSX online, for free and without signing up. Upload a file of up to 500 MB and download the XLSX result; uploaded and converted files are deleted automatically within about an hour.

Input:: SXC
Output:: XLSX
Price:: Free, no sign-up
File size:: Up to 500 MB
Your files:: Deleted automatically within about an hour

Convert legacy StarOffice Calc spreadsheets (SXC) into modern Microsoft Excel documents (XLSX) instantly. This tool is essential for users opening older archival data in contemporary office suites.

SXC is an XML-based spreadsheet format used by older StarOffice and early OpenOffice.org suites, while XLSX is the default OpenXML spreadsheet format for modern Microsoft Excel. When you convert SXC to XLSX, ConvertX translates the underlying XML schema and cell structures, ensuring that formulas, data grids, and formatting migrate accurately into the current Excel standard.

The conversion between SXC and XLSX is completely lossless, meaning your data integrity, text strings, and numerical calculations are preserved without degradation. The file size changes only insignificantly during the process.

Tips

Verify complex macros or scripts after conversion, as StarOffice Basic does not natively execute in Excel.
Ensure your SXC file is not password-protected before uploading to the converter.
Check conditional formatting rules post-conversion to guarantee identical visual presentation.

Common use cases

Migrating historical StarOffice accounting archives into current corporate Microsoft 365 workflows.
Opening legacy research datasets stored in SXC format within modern Excel environments.
Standardizing old departmental spreadsheets into the universally accepted XLSX format.

Why ConvertX stays free — forever

We built this project so anyone can convert files without paywalls, accounts, or hidden limits. Here is what that promise means in practice.

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Free tools today — and always

Every converter on ConvertX is free to use: no trials, no premium tiers, and no credit packs. We will never put core conversion features behind a subscription. Whether you convert one photo or a hundred files a week, the price stays zero.

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Privacy-first processing

Many image, audio, and video conversions run entirely in your browser. Your files never leave your device for those jobs. When server processing is required for documents or specialized formats, uploads are handled securely and removed automatically — typically within one hour.

File formats: what to choose

A quick guide to strengths and trade-offs of popular formats — so you pick the right one before converting.

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Documents

Office files, PDFs, ebooks, and plain text.

Common extensions: PDF, DOCX, XLSX, PPTX, ODT, EPUB, TXT

Advantages

+ PDF locks layout for printing and sharing
+ DOCX and ODT are easy to edit collaboratively
+ Plain text works on any device

Disadvantages

− PDF is hard to edit without special tools
− Complex layouts may shift after conversion
− Scanned PDFs need OCR for editable text

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Images

Raster and vector graphics for web, print, and photography.

Common extensions: PNG, JPG, WebP, AVIF, GIF, SVG, HEIC, TIFF

Advantages

+ WebP and AVIF offer excellent compression for the web
+ PNG keeps transparency and sharp edges
+ SVG scales without quality loss

Disadvantages

− RAW and TIFF files are large and slow to share
− JPEG loses quality on every re-save
− Some formats are not supported in older browsers

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Video

Clips, streams, screen recordings, and movies.

Common extensions: MP4, WebM, MOV, MKV, AVI, MPEG

Advantages

+ MP4 (H.264/H.265) plays almost everywhere
+ WebM is efficient for web embedding
+ MKV can hold multiple audio and subtitle tracks

Disadvantages

− High-resolution video needs lots of storage and bandwidth
− Re-encoding always takes time and may reduce quality
− Some codecs require licensing for commercial use

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Audio

Music, podcasts, voice recordings, and sound effects.

Common extensions: MP3, WAV, FLAC, OGG, AAC, M4A, OPUS

Advantages

+ FLAC and WAV preserve full quality for editing
+ MP3 and AAC are universally compatible
+ OPUS delivers great quality at low bitrates

Disadvantages

− Uncompressed WAV files are very large
− Lossy formats cannot be restored to original quality
− DRM-protected files may not convert

Frequently asked questions

Standard mathematical and logical formulas transfer seamlessly. However, proprietary StarOffice functions without direct Excel equivalents may require minor adjustments.

No, the file size changes only insignificantly because both formats utilize compressed XML-based architectures.

No, ConvertX handles the entire parsing and conversion process in the cloud without requiring any legacy software on your device.

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