By 2021, major browsers (Chrome, Edge, Firefox) treated http://localhost as “potentially secure” for some APIs but not all. The cleanest solution? Run a real HTTPS server locally.
Below is a you can adapt, based on common scenarios in 2021 where such a port was used.
: This is a specific port number. Developers use custom ports like 11501 to run unique applications (such as backend APIs, microservices, or database dashboards) without conflicting with standard ports like 80 (HTTP) or 443 (HTTPS). https localhost11501 2021
: This is the standard hostname given to the local computer network address ( 127.0.0.1 ). It allows your machine to connect to itself.
A typical web address is built from several parts, and each part of this one reveals clues about its purpose. By 2021, major browsers (Chrome, Edge, Firefox) treated
If you previously ran an application on port 11501 that strictly enforced HTTPS (HSTS), your browser might refuse to load the HTTP version of the site.
Using https with localhost can be problematic. While self-signed certificates are possible, browsers often display security warnings. Here's why you might see this: Below is a you can adapt, based on
While working on localhost is generally safe because it's not exposed to the internet, there are still important security practices to follow.
For the https://localhost:11501/2021 pattern, it is far more likely that some development framework, tool, or local application was configured to use this port. It could be a , an API gateway , a microservice , or a development container .
However, major browser updates enforced the specification. This security framework prohibits public websites or secure local apps from making asynchronous requests (like fetch() or Axios calls) to an unencrypted endpoint.