javascript - Getting status 304 for an endpoint sometimes -

i randomly receiving status code:304 not modified when looking @ network transactions json rest endpoint in chrome devtools.

const url = "/my/endpoint" let xhttp = new xmlhttprequest(); xhttp.open("get", url, true); xhttp.setrequestheader("content-type", contenttype); xhttp.send(); 

when occurs, receive same xhttp.status received previous in code. incorrect since mocked backend toggling status between 200 , 404 subsequent calls on endpoint.

it feels kind of caching taking place? how turn off?