Https Localhost 11501 Url 🎯 Must Read

The "s" stands for Secure. This means your browser expects the connection to be encrypted using TLS/SSL.

In the past, developers usually worked with plain http on localhost. However, modern web standards are strict. Features like HTTP/2, Service Workers, and secure cookies often require a secure context. If you are seeing https here, you are likely working with a modern stack that enforces security from the very beginning of the development cycle.

Since port 11501 isn't a standard industry default (like 3306 for MySQL or 5432 for PostgreSQL), seeing this URL usually implies one of three scenarios:

mkcert -install

Next.js supports HTTPS via a custom server or the --experimental-https flag (v13+): https localhost 11501 url

next dev --experimental-https --port 11501

To avoid self-signed warnings, place mkcert generated certificates in the root directory and add to next.config.js.

Any software you run (even a seemingly benign Electron app) could start a server on https://localhost:11501 and intercept or modify data sent to legitimate local services.

Since Chrome 63 (2017), Chromium-based browsers explicitly treat localhost as secure even with a self-signed certificate, provided you accept the risk. However, the key detail is that this trust is port-agnostic. So https://localhost:11501 benefits from the same exception. But in practice? Many users still see errors because of:

You will still need to click through the warning or manually add a certificate exception. The "s" stands for Secure

On your terminal (administrator/root not required):

macOS / Linux:

lsof -i :11501

or

sudo netstat -tulpn | grep 11501

Windows (PowerShell):

netstat -aon | findstr :11501

Then check the PID in Task Manager.

If nothing is listening, start your intended service.

If you want a clean, green padlock on https://localhost:11501, follow these solutions.