What are the different HTTP methods used in REST API and how do they work?

Table of Contents

• What Are HTTP Methods?
• GET Method – Retrieve Data
• POST Method – Create New Resources
• PUT Method – Update Existing Resources
• PATCH Method – Partial Update
• DELETE Method – Remove Resources
• HEAD Method – Metadata Check
• OPTIONS Method – Allowed Methods Discovery
• TRACE Method – Debugging and Diagnostics
• Quick Reference Table of HTTP Methods
• Why Knowing HTTP Methods Matters
• Conclusion
• Frequently Asked Questions (FAQs)

In the world of web development, APIs (Application Programming Interfaces) act as bridges between applications, allowing them to communicate and share data. One core concept that makes APIs work is HTTP methods—standardized instructions used to perform different actions on web resources. These methods define what kind of operation a client (like a browser or app) wants to perform on the server.

If you're learning web development, RESTful APIs, or backend systems, understanding HTTP methods is essential. This guide breaks down the most common HTTP methods used in REST APIs, along with examples and beginner-friendly explanations.

What Are HTTP Methods?

HTTP methods are actions that specify how a client interacts with a resource on a server. RESTful APIs use these methods to perform standard operations like retrieving, creating, updating, and deleting data. They map directly to CRUD operations:

• Create → POST

• Read → GET

• Update → PUT/PATCH

• Delete → DELETE

1️⃣ GET Method – Retrieve Data

• Example: GET /api/customers

  
  

• What It Does: Retrieves information from the server.

• Use Case: Displaying customer lists or fetching user profiles.

Description:
GET requests should only retrieve data. They don’t modify anything on the server. GET requests are idempotent, meaning making the same request multiple times has the same effect as making it once.

2️⃣ POST Method – Create New Resources

• Example: POST /api/customers

• What It Does: Sends data to the server to create a new resource.

• Use Case: Registering a new user, submitting a form.

Description:
POST requests send information in the request body. Unlike GET, POST can change server-side data.

3️⃣ PUT Method – Update Existing Resources

• Example: PUT /api/customers/123

• What It Does: Updates an entire resource identified by an ID.

• Use Case: Updating a user’s profile information.

Description:
PUT replaces the existing resource with the new data provided. It’s often used for full updates rather than partial changes.

4️⃣ PATCH Method – Partial Update

• Example: PATCH /api/customers/1234 { "name": "foobar" }

• What It Does: Updates part of a resource.

• Use Case: Changing only a user’s name or email address.

Description:
PATCH is more efficient than PUT for minor updates because it only changes specified fields rather than the entire resource.

5️⃣ DELETE Method – Remove Resources

• Example: DELETE /api/customers/235

• What It Does: Deletes a resource identified by an ID.

• Use Case: Deleting a user account.

Description:
DELETE requests remove resources. Repeating a DELETE request should have no additional effect, which is why it’s considered idempotent.

6️⃣ HEAD Method – Metadata Check

• Example: HEAD /api/customers

• What It Does: Retrieves headers and metadata, without the response body.

• Use Case: Checking if a resource exists before downloading it.

Description:
HEAD is like GET, but faster because it only retrieves headers—not the content.

7️⃣ OPTIONS Method – Allowed Methods Discovery

• Example: OPTIONS /api/main.html/1.1

• What It Does: Returns permitted HTTP methods for a given URL.

• Use Case: Finding out what operations are allowed on an endpoint.

Description:
OPTIONS is mainly used by browsers for CORS (Cross-Origin Resource Sharing) preflight requests.

8️⃣ TRACE Method – Debugging and Diagnostics

• Example: TRACE /api/main.html

• What It Does: Returns the exact request sent to the server.

• Use Case: Debugging network issues.

Description:
TRACE helps developers understand how a request is processed through intermediary systems like proxies or gateways.

9️⃣ CONNECT Method – Establishing Tunnels

• Example: CONNECT www.example.com:433 HTTP/1.1

• What It Does: Creates a tunnel between the client and server.

• Use Case: Used in HTTPS connections for secure communication.

Description:
CONNECT is crucial for encrypted traffic, as it enables end-to-end encrypted sessions.

Quick Reference Table of HTTP Methods

Why Knowing HTTP Methods Matters

Understanding HTTP methods helps in:

• Building APIs and web applications

• Debugging network traffic using tools like Postman or cURL

• Writing secure applications by enforcing correct request methods

• Optimizing API performance through proper use of methods like HEAD and OPTIONS

Conclusion

HTTP methods are the building blocks of web communication. Whether you're building a REST API or just consuming one, knowing how each method works is essential for effective, secure, and efficient web development.

FAQs 

What are HTTP methods in RESTful APIs?

HTTP methods are standardized request types used in RESTful APIs to perform operations like retrieving, creating, updating, and deleting resources on a server.

Why is the GET method used in REST APIs?

The GET method retrieves data from the server without making any changes to the resource.

What is the difference between GET and POST methods?

GET is used to fetch data, while POST is used to send data to the server to create new resources.

How does the PUT method work in REST APIs?

The PUT method updates an entire resource identified by its unique ID, replacing the existing data with new data.

When should you use the PATCH method instead of PUT?

PATCH is used for partial updates, modifying only specific fields in a resource rather than replacing the entire resource.

What is the DELETE method in RESTful API?

The DELETE method removes a resource from the server, usually identified by an ID.

What does the HEAD method do in HTTP communication?

HEAD retrieves the headers and metadata of a resource without downloading its full content.

What is the purpose of the OPTIONS method in HTTP?

The OPTIONS method checks which HTTP methods are allowed on a specific URL or endpoint.

How is the TRACE method useful in HTTP communication?

TRACE is used for debugging, echoing back the received request to see how it is handled by intermediate servers.

What does the CONNECT method do in HTTP?

CONNECT establishes a secure tunnel between the client and server, mainly used in HTTPS.

Which HTTP method is used to create a new user account?

POST is typically used to create a new user account in REST APIs.

Are HTTP methods case-sensitive?

Yes, HTTP methods like GET, POST, PUT are case-sensitive and should be written in uppercase.

Can a GET request have a request body?

While technically possible, a GET request should not have a body according to HTTP/1.1 specifications.

What is idempotency in HTTP methods?

Idempotency means repeating the same request multiple times has the same effect as making it once, as with GET, PUT, and DELETE methods.

Is PATCH method idempotent?

PATCH is not guaranteed to be idempotent because applying the same patch repeatedly can produce different results depending on implementation.

What is the difference between PUT and PATCH in APIs?

PUT updates the entire resource, while PATCH updates only the specified fields within a resource.

Why is POST not idempotent?

POST creates new resources, so repeating the request can create multiple resources instead of just one.

Which HTTP method is the safest to use when retrieving sensitive data?

GET is commonly used, but HTTPS should be applied to ensure data is encrypted during transit.

How do REST APIs handle multiple HTTP methods?

REST APIs define routes or endpoints where different HTTP methods correspond to different actions on the same resource.

Can DELETE method return a response body?

It can, but it's not required. Some APIs return a confirmation message; others just return a status code.

What is CORS and how does OPTIONS method relate to it?

CORS (Cross-Origin Resource Sharing) uses the OPTIONS method for preflight requests to check if the main request is safe to send.

How does HTTPS work with HTTP methods like GET and POST?

HTTPS encrypts HTTP methods and their data, securing GET, POST, and other requests from interception.

Why is understanding HTTP methods important for web developers?

Understanding HTTP methods is crucial for building secure, efficient, and well-structured APIs in web development.

How can I test different HTTP methods?

You can use tools like Postman, curl, or browser developer tools to send and inspect HTTP requests.

What does a 405 Method Not Allowed error mean?

It means the requested HTTP method is not supported on the specified endpoint.

Are all HTTP methods supported by every server?

No, some servers may restrict certain methods for security reasons or based on business rules.

What is the default method in HTML forms?

The default method in HTML forms is GET.

How do RESTful services use HTTP status codes with methods?

HTTP methods return status codes like 200 OK, 201 Created, 204 No Content, 404 Not Found, etc., based on the action’s outcome.

Can HTTP methods be customized?

No, but APIs can define custom endpoints that mimic new functionality while using standard HTTP methods.

What is the best practice for choosing between PUT and PATCH?

Use PUT for complete resource updates and PATCH for partial updates.