SDC to XLSX Converter
Convert SDC to XLSX online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
How it works
Three steps to your converted file
Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.
Upload your file
Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.
Choose an output format
Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.
Convert & download
Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.
What is an SDC file?
SDC is the legacy spreadsheet format used by StarOffice Calc and early OpenOffice.org releases, the predecessor suites to LibreOffice Calc. It stores cell data, formulas, and formatting using StarOffice's original binary document model, which was superseded by the OpenDocument Spreadsheet (ODS) standard. SDC files typically surface today only when working with archived StarOffice-era spreadsheets.
How to open an SDC file
LibreOffice Calc opens SDC files natively through its built-in legacy StarOffice format support, converting the spreadsheet into its modern editing environment automatically. Apache OpenOffice Calc also supports this older format.
SDC Technical Info
- Full Name
- StarOffice/StarCalc Spreadsheet
- Developed By
- StarDivision / Sun Microsystems
- Initial Release
- 1996
- MIME Type
- application/vnd.stardivision.calc
What is an XLSX file?
The XLSX format is the default XML-based spreadsheet file introduced in Microsoft Office 2007, adhering to the Office Open XML (OOXML) standard (ECMA-376 and ISO/IEC 29500). It replaces the binary BIFF structure of legacy XLS files with a ZIP-compressed container holding individual XML files for workbook data, worksheet structure, and metadata. By design, XLSX files strictly exclude Visual Basic for Applications (VBA) macros to prevent malware propagation, distinguishing them from the macro-enabled XLSM format.
How to open an XLSX file
As an industry-standard open format, XLSX is supported natively by Microsoft Excel, Apple Numbers, and Corel Quattro Pro. Cross-platform open-source suites like LibreOffice and Apache OpenOffice provide full read/write capabilities. Cloud-based platforms, including Google Sheets and Microsoft Excel for the Web, allow direct editing in a browser without local software installation.
XLSX Technical Info
- Full Name
- Excel Open XML Spreadsheet
- Developed By
- Microsoft
- Initial Release
- 2007
- MIME Type
- application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
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Why RunConvert
The fastest way to convert any file
Purpose-built for speed, privacy, and breadth of format support.
Convert SDC to XLSX in seconds
Every SDC to XLSX conversion runs on our servers, so your device stays fast and the output quality stays intact.
Fast, cloud-powered
No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.
Secure & private
Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.
Free - no account needed
Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.
Developer API
Convert SDC to XLSX via API
Automate SDC to XLSX conversions in three steps: create a job, upload your file, then poll for the result.
# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tag": "sdc-to-xlsx",
"tasks": {
"upload-file": {
"operation": "import/upload"
},
"convert": {
"operation": "convert",
"input": "upload-file",
"output_format": "xlsx"
},
"export-result": {
"operation": "export/url",
"input": "convert"
}
}
}'
# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.sdc
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
-H "Authorization: Bearer YOUR_API_KEY"Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.