npm start use hostname instead of localhost on Linux

My laptop uses openSUSE Linux with hostname “Guos-Kudu”. When I created a react app and run npm start, it opens http://guos-kudu:3000 in browser. When I visit http://localhost:3000 it cannot be accessed.

Some HTTP API only allows localhost to access. Or the API administrator only enabled localhost in OAuth configuration. In this situation, a non-standard URL will have many troubles.

Even when I changed the hostname to localhost or remove it, react-scripts still looks for http://guos-kudu:3000 instead of localhost. Have no idea what caused this.

[Timer]

The HOST variable is probably set in your env. Try to unset it in your terminal session.

If that works, create a .env.local file which contains the following:

HOST=localhost

You can now run npm start without worrying about unsetting HOST.

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To achieve the default CRA behavior, use 0.0.0.0 instead of localhost.

[Timer]

You might want to check your ~/.bashrc or similar (~/.profile, ~/.bash_profile, ~/.bash_profile, ~/.login, etc).