Cache-control header doesn't work for IE11

Question

Can someone explain me behaviour of IE11?

As I got, all browsers which support Http 1.1 (except some versions with bugs), have support of Cache-Control header.

I have backend which has Access-Control-Request-Headers with Cache-Control and If-Modified-Since only, so I can't use Expires or Pragma. In my case, IE11 has strange behaviour.

Any directives of Cache-Control not work for me at all in IE11. IE11 just cache all requests with such headers:

• Cache-Control: no-cache
• Cache-Control: no-store, no-cache
• Cache-Control: no-cache, max-age=0
• Cache-Control: no-store, no-cache, max-age=0, must-revalidate
• and any other combinations of directives.

Interesting fact that just adding If-Modified-Since: 0 solves my issue.

Why IE11 (I tried it on many PC) ignores Cache-Control at all and just caches all data?

Request's Headers:

   Accept: */*
   Accept-Encoding: gzip, deflate
   Access-Control-Request-Headers: cache-control, expires, accept-language, x-website-token, authorization, x-website-config, accept
   Access-Control-Request-Method: GET
   Cache-Control: no-cache
   Content-Length: 0
   Host: ----
   Origin: ----
   User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Response's Headers:

   access-control-allow-credentials: false
   access-control-allow-headers: DNT, User-Agent, X-Website-Token, X-Website-Config, X-Website-Dgp, X-Integration-Id, X-Requested-With, If-Modified-Since, Cache-Control, Content-Type,Range, Accept, Accept-Language, Authorization, DNT
   access-control-allow-methods: GET, POST, PUT, PATCH, DELETE, OPTIONS
   access-control-allow-origin: *
   access-control-expose-headers: X-Pagination-Total-Count, X-Pagination-Page-Count, X-Pagination-Current-Page, X-Pagination-Per-Page
   access-control-max-age: 3600
   content-type: application/json; charset=UTF-8
   date: Sat, 13 Jun 2020 23:01:32 GMT
   server: nginx/1.16.1
   set-cookie: x-last-referrer=;Domain=-----;Path=/;
   x-release-version: 1

Answer 1

First, Internet Explorer supports the HTTP 1.1 Cache-Control header, which prevents all caching of a particular Web resource when the no-cache value is specified by an HTTP 1.1 server.

Second, the Cache-Control HTTP header holds directives (instructions) for caching in both requests and responses. A given directive in a request does not mean the same directive should be in the response.

So, to prevent cache the response resource, we could set the cache-control: no-cache in response and set the Expires to "-1". Another method, as you said, updates the page via a conditional If-Modified-Since request. More detail information, please check this article: How to prevent caching in Internet Explorer.