How to get value of custom http header?

I checked amazon.com website for retrive X-Amz-Cf-Id header which I belive is not a standard header and for me it is working fine:

function wpse_288865_featch_header() {

    $response = wp_remote_get('https://www.amazon.com/');
    $custom_header = wp_remote_retrieve_header($response, 'X-Amz-Cf-Id');

    var_dump($custom_header);
    exit;
}

add_action('init', 'wpse_288865_featch_header');

Sometimes amazon.com is not returning this header so please refresh your WordPress site couple of times.

I also inspected WordPress core for parsing request and didn’t found some kind of whitelist of headers. It is only removing transfer-encoding and connection headers.

Please check if you make proper request to your site. For the first time I have checked google.com and have similar issue. I couldn’t get the headers which I’ve seen that google.com should return. Problem was that google.com do not allow me to make such a request and in return I get HTTP/1.1 403 Forbidden response which obviously return completely different headers that HTTP/1.1 200 response.

Related Posts:

  1. Should a 502 HTTP status code be used if a proxy receives no response at all?
  2. What is the difference between a URI, a URL and a URN?
  3. HTTP Status 504
  4. What is the difference between POST and GET? [duplicate]
  5. Do I need Content-Type: application/octet-stream for file download?
  6. Problem HTTP error 403 in Python 3 Web Scraping
  7. application/x-www-form-urlencoded or multipart/form-data?
  8. Problem HTTP error 403 in Python 3 Web Scraping
  9. application/x-www-form-urlencoded or multipart/form-data?
  10. Is 418 “I’m a teapot” really an HTTP response code?
  11. How to define the basic HTTP authentication using cURL correctly?
  12. How to define the basic HTTP authentication using cURL correctly?
  13. “Cannot GET /” with Connect on Node.js
  14. “CAUTION: provisional headers are shown” in Chrome debugger
  15. What’s the difference between a POST and a PUT HTTP REQUEST?
  16. How do I send a POST request with PHP?
  17. Why is it said that “HTTP is a stateless protocol”?
  18. What’s the difference between using application/csv vs text/csv? [duplicate]
  19. What are all the possible values for HTTP “Content-Type” header?
  20. What is the difference between PUT, POST and PATCH?
  21. What’s the difference between “Request Payload” vs “Form Data” as seen in Chrome dev tools Network tab
  22. Exception in thread “main” java.net.NoRouteToHostException: No route to host
  23. ndroid 8: Cleartext HTTP traffic not permitted
  24. Can PHP cURL retrieve response headers AND body in a single request?
  25. Setting Curl’s Timeout in PHP
  26. How are parameters sent in an HTTP POST request?
  27. Why am I suddenly getting a “Blocked loading mixed active content” issue in Firefox?
  28. wget: unable to resolve host address `http’
  29. Are HTTP headers case-sensitive?
  30. When looking at the differences between X-Auth-Token vs Authorization headers, which is preferred?
  31. WordPress HTTP parameter pollution
  32. Does WordPress send data about your blog to WordPress.org or Automattic?
  33. Hiding WordPress REST API v2 endpoints from public viewing
  34. Does WordPress only support HTTP 1.1?
  35. How do I troubleshoot responses with WP HTTP API?
  36. Is curl required?
  37. The resource was preloaded using link preload but not used within a few seconds
  38. using wp_remote_get to retrieve own url on local host
  39. Using wp-cron in backpress – problems with wp_remote_post, fsockopen error
  40. Running index.php from command line & load balancer health checks
  41. Enable CORS in wordpress
  42. Change port of wordpress
  43. Several times request to load plugins when sending one request
  44. why is $_REQUESt[‘redirect_to’] empty?
  45. Get “HTTP/1.1 406 Not Acceptable” when accesing my website with Delphi Indy Control
  46. WordPress HTTP 500 Error “page isn’t working”
  47. What’s the point in having “www” in a URL?
  48. For what is the “.well-known”-folder?
  49. Human readable format for http headers with tcpdump
  50. How to make wireshark filter POST-requests only?
  51. Image file urls still point to http instead of https
  52. SOAP vs REST (differences)
  53. How to redirect all HTTP requests to HTTPS
  54. How to use java.net.URLConnection to fire and handle HTTP requests
  55. Access-Control-Allow-Origin Multiple Origin Domains?
  56. How to handle ETIMEDOUT error?
  57. How to send HTTP request in java? [duplicate]
  58. How to send a GET request from PHP?
  59. “Cross origin requests are only supported for HTTP.” error when loading a local file
  60. What is ‘xmlhttp.setRequestHeader();’ and in which situations is it used?
  61. Why is WordPress redirecting from http to https on a local environment?
  62. Switch from https back to http
  63. HTTP request on localhost failing
  64. Remove HTTP: from the site URL and just keep // in it
  65. WordPress – https : Css and Js files are not working (load on http instead of https)
  66. Remove the http protocol from images
  67. Access general settings trough wordpress files
  68. Divert http to https with WordPress on IIS
  69. POST request not going through?
  70. Changing HTTP to HTTPS
  71. WordPress changing script source from https to http
  72. All content is HTTPS, but browsers warn of HTTP mixed content [closed]
  73. Errors on a single host using wp_remote_get() unless sslverify is set to false
  74. Strange behavior: random HTTP error 500 fixed by visiting Permalinks settings page (htaccess issue with language code)
  75. My site doesn’t redirect from HTTP to HTTPS
  76. Page can’t hand request – HTTP ERROR 500 – when updating something
  77. https to https problem – 404 and can’t login
  78. HTTP error when uploading an image
  79. Broken css on mobile phones only on https
  80. Colon is Missing In My Website Url in WordPress Shortcode
  81. Trouble when I try to connect to WordPress
  82. Redirecting specific sites to HTTP in WordPress Multisite
  83. Plesk login inaccessible after changing site URL
  84. mixed contents admin panel is Unsecured
  85. Moving wordpress site from HTTP to HTTPS ERR_TOO_MANY_REDIRECTS
  86. Implications of not completing all tasks when switching to HTTPS
  87. Require advice handling a URL redirect from a Third Party. URL Params need to populate and then forward to payment
  88. Redirect HTTP request to HTTPS request
  89. My WP Website Shows HTTP ERROR 500
  90. Moving site from HTTP to HTTPS
  91. Accessing content from third party as native posts in WordPress
  92. Is it safe to use PUT and DELETE requests
  93. Duplicator live to wamp https to http
  94. How to reply with 200 from Nginx, without serving a file?
  95. How to list Apache enabled modules?
  96. How do high traffic sites service more than 65535 TCP connections?
  97. Best way to redirect all HTTP to HTTPS in IIS
  98. How do you modify HTTP response headers on feed/?
  99. Development to production, how to move a development site from http + dev.example.com to a production site https + example.com?
  100. How do I make the block editor use https by default?