Stop using (HTTP 1.0) | Replaced with (HTTP 1.1 since 1999) |
---|---|
Expires: [date] | Cache-Control: max-age=[seconds] |
Pragma: no-cache | Cache-Control: no-cache |
If it's after 1999, and you're still using Expires or Pragma, you're doing it wrong.
I'm looking at you Stackoverflow:
200 OK Pragma: no-cache Content-Type: application/json X-Frame-Options: SAMEORIGIN X-Request-Guid: a3433194-4a03-4206-91ea-6a40f9bfd824 Strict-Transport-Security: max-age=15552000 Content-Length: 54 Accept-Ranges: bytes Date: Tue, 03 Apr 2018 19:03:12 GMT Via: 1.1 varnish Connection: keep-alive X-Served-By: cache-yyz8333-YYZ X-Cache: MISS X-Cache-Hits: 0 X-Timer: S1522782193.766958,VS0,VE30 Vary: Fastly-SSL X-DNS-Prefetch-Control: off Cache-Control: private
tl;dr: Pragma
is a legacy of HTTP/1.0 and hasn't been needed since Internet Explorer 5, or Netscape 4.7. Unless you expect some of your users to be using IE5: it's safe to stop using it.
[date]
(deprecated - HTTP 1.0)[seconds]
And the conditional requests:
Etag: W/“1d2e7–1648e509289”
If-None-Match: W/“1d2e7–1648e509289”
304 Not Modified
last-modified: Thu, 09 May 2019 19:15:47 GMT
If-Modified-Since: Fri, 13 Jul 2018 10:49:23 GMT
304 Not Modified
last-modified: Thu, 09 May 2019 19:15:47 GMT