When I load my web app via localhost (which is not served via HTTPS), I find that the CSS and JavaScript assets fail to load, because the browser tries to access them via https://localhost:3000/style.css and https://localhost:3000/script.js. The website itself (index.html) is served via HTTP.

In the document , both assets are included via their relative path, so the browser must be defaulting to HTTPS to retrieve all assets.

I already checked the HSTS setting on my server and made sure that it is turned off during development. I also cleared the HSTS cache in my browser, to no avail.

Any pointers to where I should look next would be greatly appreciated!