What is the MIME type of .xls files?
The MIME type (media type) for Microsoft Excel (legacy) files with the .xls extension is application/vnd.ms-excel. The binary format used by Excel 97–2003.
Content-Type header
Content-Type: application/vnd.ms-excelServer configuration
| Server | Configuration |
|---|---|
Nginx (mime.types or types {}) | application/vnd.ms-excel xls; |
Apache (.htaccess) | AddType application/vnd.ms-excel .xls |
IIS (web.config) | <mimeMap fileExtension=".xls" mimeType="application/vnd.ms-excel" /> |
| Node.js / Express | res.type('xls') or res.setHeader('Content-Type', 'application/vnd.ms-excel') |
| Amazon S3 | Set Content-Type: application/vnd.ms-excel on the object (metadata), or pass --content-type application/vnd.ms-excel to aws s3 cp |
Should .xls files be compressed?
Yes. Microsoft Excel (legacy) is uncompressed data, so enabling gzip or Brotli for application/vnd.ms-excel typically saves 50–80 % of the transfer size. Make sure your server’s compression list includes this type — check with the website compression test.
Why the MIME type matters
Browsers decide what to do with a response — render, run, play or download — from the Content-Type header, not the file extension. With X-Content-Type-Options: nosniff, a wrong type causes stylesheets and scripts to be blocked outright. For uploads, never trust the type sent by the client; check the file’s content (its magic bytes) on the server.
Frequently asked questions
What is the MIME type for .xls?
application/vnd.ms-excel.How do I set the Content-Type for .xls in Nginx?
application/vnd.ms-excel xls; is listed in the types block (usually in /etc/nginx/mime.types) and reload Nginx.