How To Access Firebase From Http://localhost:3000

I'm developing a React app, and I get this error when trying to sign in to Firebase using their email auth provider.

Failed to load 
Response to preflight request doesn't pass access control check: The
'Access-Control-Allow-Origin' header has a value 'https://localhost:3000' 
that is not equal to the supplied origin. Origin 'http://localhost:3000'
is therefore not allowed access.

(Notice the https on line 3 versus http on line 4)

It looks like they changed Access-Control-Allow-Origin from *, to the https version of whatever domain you're calling from?

Does this mean I now need to configure my React app to run as https://localhost:3000?



You want to create a .env file in the root of your project and set HTTPS=true. This will launch your app using a self signed certificate.

Take a look at the advanced configuration options of create-react-app here

If you need more control over the certificate and do not want to eject. Take a look at react-app-rewired ( You can config the devServer to use a custom certificate using the Extended Configuration Options here (