azurewebsites.net This site can’t provide a secure connection

Question

Browsing to my app service URL azurewebsites.net domain results in an SSL error.

This site can’t provide a secure connection

Answer 1

Hi @JC,

Thank you for reaching us regarding an SSL error when trying to access your app service URL, and the browser is indicating that it can't establish a secure connection.

In Azure App Service, the default https://<app>.azurewebsites.net hostname is normally secured automatically by an Azure-managed wildcard certificate, so no certificate configuration is required for that URL.

If you’re seeing an SSL error, it’s typically because the request is being redirected to a different hostname (for example, forcing www or forcing your custom domain), or because a custom domain certificate/binding is missing or bound to the wrong hostname.

If your browser reports that the certificate is invalid and "This site can’t provide a secure connection”, it is usually due to one of the following reasons:

1. Application‑level redirect:
   Please check whether your application/app settings are redirecting azurewebsites.net traffic to www.<app>.azurewebsites.net or to a custom domain. If so, ensure the redirect target hostname has a valid TLS/SSL binding.
2. Custom domain certificate/binding issue
   If you are using a custom domain, make sure the SSL certificate is valid (not expired) and correctly bound to the exact hostname being accessed (for example, example.com versus www.example.com). A mismatch between the hostname and the certificate can cause a browser SSL error. To fix this, go to the Microsoft Azure portal > navigate to your App Service > TLS/SSL settings, and confirm that the correct certificate is properly bound to each custom hostname you are using.
3. Incorrect SSL binding configuration
   In rare cases, an incorrect TLS/SSL binding configuration—such as conflicting SNI or IP-based bindings, can cause the wrong certificate to be presented to users. To resolve this, review all TLS/SSL bindings configured for the app in the Azure portal and ensure there are no conflicting, duplicate, or unnecessary bindings that could interfere with the correct certificate being served.
4. Intermittent or client‑side validation issues
   Sometimes SSL errors are caused by browser cache, local DNS, or network security software rather than a server issue. Try clearing your browser cache, using an incognito window, or testing the site from a different browser or network.

Reference:
https://learn.microsoft.com/en-us/troubleshoot/azure/app-service/troubleshoot-azure-app-service-certificates
https://learn.microsoft.com/pt-br/troubleshoot/azure/app-service/connection-issues-with-ssl-or-tls/troubleshoot-domain-and-tls-ssl-certificates
https://learn.microsoft.com/en-us/azure/app-service/configure-ssl-certificate?tabs=apex%2Crbac%2Cazure-cli

Kindly let us know if the above comment helps or you need further assistance on this issue.

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Answer 2

The SSL error you are encountering when trying to access your Azure App Service URL could be due to several reasons. Here are some common causes and solutions:

1. Certificate Not Bound: Ensure that your custom domain has an SSL certificate bound to it. If the certificate is not bound, Azure will not serve your certificate, resulting in an SSL error.
2. Incorrect Domain in Certificate: The SSL certificate must match the domain you are trying to access. If your certificate is configured for a different address, such as https://www.yourdomain.com, but you are accessing azurewebsites.net, this mismatch will cause an error.
3. SSL Configuration Issues: If you have recently made changes to your SSL configuration, it may take some time for those changes to propagate. You can also manually sync the certificate if you suspect that the app service hasn't updated with the new certificate.
4. DNS Caching: Sometimes, your browser or local DNS cache may still point to an old IP address. You can try clearing your browser cache or flushing your DNS cache using the command ipconfig /flushdns on Windows.
5. SNI and IP SSL Bindings: If you are using both SNI and IP SSL bindings, ensure that they are configured correctly. Mixing these can lead to presenting the wrong certificate.

By checking these aspects, you should be able to resolve the SSL connection issue with your Azure App Service.

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References:

• Troubleshoot custom domain issues in Azure App Service for web apps on Windows and Linux
• Troubleshoot domain and TLS/SSL certificate problems in Azure App Service