Every HTTP request has a set of mandatory and optional headers.
We have a lot of them, but here I’ll list you the most important / useful ones.
Host
Host: flaviocopes.com
The domain name of the server, and the port number on which the server is listening. If the port is omitted, 80 is assumed.
This is the only mandatory HTTP request header
All the other headers are listed in alphabetical order.
Accept
Accept: application/json
The MIME type we’ll want the response to be
Accept-Charset
Accept-Charset: utf-8
Lists the charset we’ll want the response to be
Accept-Encoding
Accept-Encoding: gzip, deflate
List of acceptable encodings we’ll want the response to be
Accept-Language
Accept-Language: en-US
List of languages we’ll want the response to be
Authorization
Authorization: Basic 34i3j4iom2323==
To pass authentication credentials, for example a token
Cache-Control
We can set the caching rules using this header.
Cache-Control: no-cachetells the server to revalidate the data before sending the response to make sure it’s currentCache-Control: max-age=30tells the server we want data that’s not older than 30 seconds
Content-Length
Content-Length: 348
The length of the request body in bytes
Content-Type
Content-Type: application/x-www-form-urlencoded
The content type of the body of the request (used in POST and PUT requests).
Cookie
Cookie: name=value
Sets a cookie
Referer
Referer: https://flaviocopes.com
The address of the previous web page from which a link to the currently requested page was followed.
User-Agent
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36
The string that identifies the user agent (the browser)
Lessons in this unit:
| 0: | Introduction |
| 1: | An HTTP request |
| 2: | HTTP Methods |
| 3: | HTTP Status Codes |
| 4: | HTTP Client/Server communication |
| 5: | ▶︎ HTTP Request Headers |
| 6: | HTTP Response Headers |
| 7: | HTTPS |
| 8: | HTTP/2 |
| 9: | HTTP/3 |