The XMLHttpRequest Object

The getAllResponseHeaders() function returns all the header information of a resource, like length, server-type, content-type, last-modified, etc:

alt-svc: h3=":443"; ma=86400 cf-cache-status: DYNAMIC cf-ray: 92acdb550b4afa1b-ORD content-encoding: zstd content-type: text/plain date: Fri, 04 Apr 2025 00:58:20 GMT last-modified: Sat, 16 Oct 2021 13:45:10 GMT nel: {"success_fraction":0,"report_to":"cf-nel","max_age":604800} report-to: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v4?s=V4LzvWFXiIeWdF0v0I6m4k7U9MyKYEIlcuzeAdNLqB4L4hLxBmZiFXuk%2Bk8Y5L9gyHuvg3IzHcrNCYxEGHYgOTSMxi5TPubvmUQQ%2Fn7Wh%2BeFsmp2qr3ybARO7ALlchaYBGUC"}],"group":"cf-nel","max_age":604800} server: cloudflare x-content-type-options: nosniff