Chrome not caching preflight

Question

I'm implementing a REST API that should support cross domain requests. Using CORS I want to achieve this. Almost all of my requests are 'not-simple', meaning for all non-GET requests a preflight request must be send by the browser.

To limit the amount of preflight/OPTIONS requests I try to let the browser cache the OPTIONS requests. This seems to work in Firefox and Safari, but not in Chrome. I know Chrome will only cache the preflight requests for only 10 minutes, but in my case it seems no caching takes place at all.

These are the HTTP requests and responses sent/received by Chrome:

Request:

OPTIONS /api/v1/sessions HTTP/1.1
Host: xxxxxxx
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
Access-Control-Request-Method: POST
Origin: http://localhost:8000
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.107 Safari/537.36
Access-Control-Request-Headers: content-type
Accept: */*
Referer: http://localhost:8000/
Accept-Encoding: gzip, deflate, sdch
Accept-Language: nl-NL,nl;q=0.8,en-US;q=0.6,en;q=0.4

Response:

HTTP/1.1 200 OK
Date: Sun, 26 Jul 2015 09:33:27 GMT
Server: Apache/2.4.7 (Ubuntu)
X-Powered-By: PHP/5.5.9-1ubuntu4.9
Cache-Control: private, max-age=1440, pre-check=1440
Access-Control-Allow-Origin: http://localhost:8000
Access-Control-Allow-Methods: GET,POST,PATCH,DELETE
Access-Control-Max-Age: 86400
Access-Control-Allow-Headers: content-type
Content-Length: 0
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=utf-8

Answer 1

You have Pragma: no-cache & Cache-Control: no-cache headers set in the request.
Try removing them.

Api requests by default do not set these headers, and I doubt chrome does either.
You should check your code and find out where they are set from.

Now, given that its working fine on other browsers, you'd better check if you have set no-cache option on Dev Tools.