On the web, clients, such as a browser, for example, communicate with different web servers with the help of the HTTP protocol, which regulates how the client has to formulate its requests and how the server has to respond. The HTTP protocol employs several different request methods. In this guide you will know the details of the most common ones..
GET is the mother of all HTTP requests. This request method existed as early as the world wide web and is used to request a resource , such as an HTML file, from the web server .
When you type the URL www.example.com into your browser, it connects to the web server and sends it a GET request:
GET /index.php
The index.php file in this request code sample is the home page of a website, which the server will send in response to the browser..
The request for the address www.example.com/test.html would be formulated in the same way:
GET /test.html
The server would send the file test.html as a response.
More information can be added to the GET request , with the intention that the web server also processes it. These so-called URL parameters are attached to the URL. The syntax is quite simple:
Let's see it with this example: to search for certain offers on the website of a software company, the GET request will indicate? Windows? as a platform and? Office? as a category:
GET /search?platform=Windows&category=office
Request sequences need special encoding, because many special characters have different meanings. For example, the text? HTTP List? It must be encoded as follows to be accepted as a request sequence:
GET /search?thema=Lista%20HTTP
It is very easy to encode URLs with online tools, such as this URL decoder, or offline with Excel's URLCODIF function ..
When large packets of data, such as images or private form data, for example, have to be sent to the web server, the GET method falls short, because all the data that is transmitted is written open in the address bar of the browser.
In these cases, the POST method is used. This method does not write the URL parameter in the URL, but rather appends it to the HTTP header.
POST requests are often used with digital forms . Below you will find an example of a form that collects a name and an email address and sends it to the server via POST:
<html> <body> <form action="newsletter.php" method="post"> Name: <input type="text" name="name"><br> E-mail: <input type="text" name="email"><br> <input type="submit"> </form> </body> </html>
In our guide you will find information to understand the difference between GET and POST.
The HTTP HEAD request method is used to request that the server only send the response header, without the file. This alternative is convenient when very large files have to be transferred, since, with this request, the client first knows the size of the file in order to later decide whether to accept it or not.
For example:
HEAD /downloads/video1.mpeg HTTP/1.0
In the header that the server sends in response, the client finds the data about the file size in the? Content-length? Field:
With the OPTIONS method, the client can ask the server what methods it supports for the file in question.
OPTIONS /download.php
The answer could be something like this:
In the field? Allow? the server informs the client that it supports the OPTIONS, GET, HEAD and POST methods. In the? Content-length? Field, the figure 0 indicates that no file has been sent, only the header.
With the TRACE method, you can follow the path that an HTTP Request follows to the server and from there back to the client. This trace can be run on Windows with the tracert command . You just have to enter the following command in the console ( cmd.exe ):
tracert www.example.com
Some methods can only be applied in certain contexts. This is the case with the CONNECT method, which creates a direct and protected connection through a proxy ( tunneling ), or several methods that are related to WebDAV: PATCH, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK.
PUT, PATCH, and DELETE are used to save , modify, or delete files on the server . In common web programming, these methods play little role, as the server blocks them for security, but they are used in the context of WebDAV and REST APIs.
