Understanding cURL command
After reading this article you will have the understanding of cURL command and you will also get to know the must-know cURL commands as a developer and their uses.
Before jumping directly on cURL, we shall go through with a easy flow to get most from this article.
What is server and why is it necessary to talk to it?
Server is simply a computer which is on 24×7 and gives repose to request to client computer. It is important to talk to it as database lives behind it, websites live here, APIs live here and authentication happens on server along with many other thing which can be handled by anything but servers.
We always use browsers to talk to servers. But, have you ever wondered does things actually run as cleanly and smoothly as it appears? Well, no …not all. Browsers just handle many things behind the scene without you knowing things. Let us understand with a fun example. Browsers are like those fancy restaurant where there’s beautiful interior design, music in the background, good service management. You simply tell the waiter your dishes and you get your food nicely plated. Now imagine food buffets where you get your food on you own, where there is no waiter and fanciness. Getting your food with all the fanciness is browsing your request and getting your food on your own is using cURL.
In one line, cURL is the terminal command, which gives you response in raw form.
Programmers often does not need UI, clicking just a response to their request, that’s when cURL is best for.
Simple cURL command
When you run:
curl https://www.google.com
It responds with something like this:
<!doctype html>
<html>
<head>...</head>
<body>...</body>
</html>
Understanding request and response
Request is what you send to the server — where you want to go and what you want from it.
Response is what the server sends back after processing your request.
In simple words:
Request → your question
Response → server’s answer
When you run:
curl https://www.google.com
You are sending a request that means:
“Hey server, give me whatever lives at this address.”
The server replies with a response, which contains two important things:
Status – tells whether your request succeeded or failed
Data – the actual content (HTML, JSON, text, etc.)
What does the response actually mean?
When cURL prints something like:
<!doctype html>
<html>
<head>...</head>
<body>...</body>
</html>
It means:
Your request reached the server
The server understood your request
The server successfully returned data
This HTML is the same thing your browser receives —
the browser just renders it nicely, while cURL shows it as-is (raw).
GET and POST (only the basics)
To talk to servers, we mainly use HTTP methods.
For now, you only need to understand two of them.
GET – “Give me something”
GET is used when you want to fetch data.
Examples:
Opening a website
Fetching user data
Reading information
curl https://example.com
This is a GET request, even if you don’t write GET explicitly.
POST – “Here is something for you”
POST is used when you want to send data to the server.
Examples:
Login forms
Creating users
Submitting data
Conceptually, POST means:
“I am sending you some data. Please process it.”
We’ll use POST in later examples — for now, just understand why it exists.
Why programmers love cURL
Programmers use cURL because:
No UI required
No clicking
No browser magic
Just request → response
cURL helps answer questions like:
Is the server running?
Is the API returning correct data?
Is the problem in frontend or backend?
What is the server actually responding with?
If cURL works but browser doesn’t → frontend issue
If cURL fails → backend or network issue
Browser and Curl
Browser renders your request in fancy version while cURL shows you the real thing happening behind the scene.
Final thoughts
cURL may look simple, but it is one of the most powerful tools a developer can learn.
It helps you understand how the web actually works — not the fancy version shown by browsers, but the real communication happening underneath.
Once you are comfortable with basic cURL commands, learning APIs, backend systems, networking, and DevOps becomes much easier.
