An Azure service that provides an event-driven serverless compute platform.
Hi @Muthusamy, Reegan ,
It sounds like the Function App blade is loading really slowly because the Azure portal UI needs to make a bunch of outbound calls (to your *.azurewebsites.net site, the Kudu site at *.scm.azurewebsites.net, and various Azure Management APIs). If any of those calls are blocked or slow to respond, the portal blades hang or load very slowly.
Here are a few things to check and try:
- Open your browser’s F12 Dev Tools → Network tab when you load the Function App blade. Look for calls to
<yourapp>.azurewebsites.net,<yourapp>.scm.azurewebsites.net, or management.azure.com. Any failures/delays there point to networking or backend issues. - If you’re running inside an Internal Load-Balanced App Service Environment (ILB ASE) or using Private Endpoints:
- Make sure your workstation (or jump box) is on the same VNet.
- Confirm your DNS settings (hosts file or DNS server) resolve the *.azurewebsites.net and *.scm.azurewebsites.net names.
- Ensure the portal’s function site URL is added to your Function App’s CORS rules.
- Verify the SSL certificate chain is trusted by your client.
- Check Azure Service Health (in the portal or via CLI) for any ongoing backend or portal incidents that could be impacting performance.
- Investigate SNAT port usage: if your App Service plan has exhausted its outbound SNAT ports, calls to backend APIs can hang. You can view SNAT port metrics under your App Service Plan’s Metrics blade.
- As a workaround when the portal is unresponsive:
- Use Azure CLI or PowerShell to change your Function App settings.
- Try a different browser or an incognito/private session to rule out caching/extensions.
- Finally, because portal slowness can be transient, try again a little later sometimes the backend slowly recovers on its own.