XLTX to XLSX Converter
Convert XLTX to XLSX online for free. Fast, secure, and high-quality conversion with no sign-up or software required.
Maximum file size is 1GB
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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 XLTX file?
The XLTX format is the standard, macro-free template file for Microsoft Excel 2007 and later, adhering to the ISO/IEC 29500 OOXML standard. It uses a ZIP-compressed directory of XML text files to define spreadsheet layouts, styles, and formulas. Unlike XLTM, the XLTX specification explicitly forbids the storage of VBA code, ensuring that templates remain secure and free of macro-based viruses when distributed across enterprise networks.
How to open an XLTX file
XLTX files open natively in Microsoft Excel 2007 and newer on Windows and macOS. When opened, the software creates a new, untitled workbook based on the template rather than editing the XLTX file directly. Compatibility extends to LibreOffice Calc, Apache OpenOffice, and PlanMaker, allowing for cross-platform template usage without requiring the Microsoft Office suite.
XLTX Technical Info
- Full Name
- Excel Open XML Template
- Developed By
- Microsoft
- Initial Release
- 2007
- MIME Type
- application/vnd.openxmlformats-officedocument.spreadsheetml.template
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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Every XLTX to XLSX conversion runs on our servers, so your device stays fast and the output quality stays intact.
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Developer API
Convert XLTX to XLSX via API
Automate XLTX 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": "xltx-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 "$UPLOAD_URL" --upload-file input.xltx
# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$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.