Speedtest.net Mini is compatible with all major web server software, but may require some configuration to function properly. Often, administrators experience issues with the upload test, which POSTs data to the upload file in your installation. Here are some tips about how to fix common causes of these upload errors:

• Make sure you're using the right upload file for your server. The Speedtest.net Mini installation includes files for PHP, ASP, ASPX and JSP for maximum compatibility. Choose the index HTML file that uses the appropriate language for your server, or the upload test will fail.
• Ensure that your maximum HTTP post size is high enough. Our documentation wiki has instructions on how to increase your maximum HTTP post size on Apache and IIS.
• If running lighttpd, make sure your server can accept "Expect: 100-continue" headers. Versions 1.4.21 and afterwards can use this setting for Speedtest.net compatibility: server.reject-expect-100-with-417 = "disable"

If you're continuing to experience errors, you may want to ensure your installation was setup correctly. Check out these step-by-step instructions for guidance.