What Are HTTP Methods and When Should I Use GET, POST, PUT, or DELETE?
HTTP methods are the invisible force behind every digital interaction you make – from liking social media posts to transferring money between accounts. For developers and anyone building web applications, choosing the right HTTP method isn’t just a technical detail – it’s what prevents duplicate orders, lost updates, and security vulnerabilities that could expose your users’ data. Let’s explore why these methods matter to both the apps you build and the ones you use every day.
HTTP Methods Overview
Section titled “HTTP Methods Overview”Here’s a quick reference for the essential HTTP methods:
GET: Retrieve data
Section titled “GET: Retrieve data”Safe: ✅ Yes
Idempotent: ✅ Yes
Has Body: ❌ No
POST: Create new resource
Section titled “POST: Create new resource”Safe: ❌ No
Idempotent: ❌ No
Has Body: ✅ Yes
PUT: Replace entire resource
Section titled “PUT: Replace entire resource”Safe: ❌ No
Idempotent: ✅ Yes
Has Body: ✅ Yes
PATCH: Partial update
Section titled “PATCH: Partial update”Safe: ❌ No
Idempotent: ❌ No
Has Body: ✅ Yes
DELETE: Remove resource
Section titled “DELETE: Remove resource”Safe: ❌ No
Idempotent: ✅ Yes
Has Body: ❌ Usually No
HEAD: Get metadata only
Section titled “HEAD: Get metadata only”Safe: ✅ Yes
Idempotent: ✅ Yes
Has Body: ❌ No
OPTIONS: Check available methods
Section titled “OPTIONS: Check available methods”Safe: ✅ Yes
Idempotent: ✅ Yes
Has Body: ❌ No
We’ll explain “Safe” and “Idempotent” concepts as we explore each method.
The Restaurant Operations Framework
Section titled “The Restaurant Operations Framework”Let’s use a restaurant analogy to understand how different HTTP methods work like different types of operations at a sophisticated restaurant.
GET: Retrieve data without changing anything on the server.
Section titled “GET: Retrieve data without changing anything on the server.”Like viewing the menu or checking your reservation status. You’re looking at information that already exists, and your viewing doesn’t change anything.
Key Characteristics
Section titled “Key Characteristics”- It is SAFE because it never modifies server data
- IDEMPOTENT because calling it multiple times has the same effect
- CACHEABLE because results can be stored for faster future access
- NO REQUEST BODY: All parameters go in the URL
Why is GET Safe and Idempotent?
Section titled “Why is GET Safe and Idempotent?”💡 Whether you check the menu once or a hundred times, the menu doesn’t change and you get the same information each time.
POST: Create something new on the server.
Section titled “POST: Create something new on the server.”Like making a new reservation or placing a new order. Each time you do this, you’re adding something new to the system.
- NOT SAFE: Modifies server state
- NOT IDEMPOTENT: Each call creates a new resource
- HAS REQUEST BODY: Data for the new resource
- RETURNS CREATED RESOURCE: Usually includes new ID
Why is POST Not Idempotent?
Section titled “Why is POST Not Idempotent?”💡 If you submit the same article three times, you’ll get three separate articles with different IDs.
PUT: Replace an entire resource with new data.
Section titled “PUT: Replace an entire resource with new data.”Like completely changing your reservation – new date, new time, new party size, new special requests. Everything gets replaced with the new information.
Key Characteristics
Section titled “Key Characteristics”- NOT SAFE: Modifies server state
- IDEMPOTENT: Multiple identical calls have the same result
- HAS REQUEST BODY: Complete new resource data
- REPLACES ENTIRELY: All fields are updated, missing fields are removed
Why is PUT is Idempotent?
Section titled “Why is PUT is Idempotent?”💡 Sending the same complete update multiple times results in the exact same final state.
PATCH: Modify only specific fields of a resource (partial update).
Section titled “PATCH: Modify only specific fields of a resource (partial update).”Like changing just the time of your existing reservation while keeping everything else the same – the date, party size, and special requests remain unchanged.
Key Characteristics
Section titled “Key Characteristics”- NOT SAFE: Modifies server state
- NOT IDEMPOTENT: Results can vary depending on current state
- HAS REQUEST BODY: Only the fields to change
- PARTIAL UPDATE: Only specified fields are modified
Why is PATCH is Not Idempotent?
Section titled “Why is PATCH is Not Idempotent?”💡 If you increment a view counter with PATCH, each call increases the number differently.
DELETE: Remove a resource from the server.
Section titled “DELETE: Remove a resource from the server.”Restaurant Analogy
Section titled “Restaurant Analogy”Like canceling your reservation. Once it’s canceled, the reservation no longer exists in their system.
Key Characteristics
Section titled “Key Characteristics”- NOT SAFE: Modifies server state
- IDEMPOTENT: Deleting the same thing multiple times has the same result
- USUALLY NO BODY: The URL identifies what to delete
- RETURNS STATUS: Confirms successful deletion
Why is DELETE Idempotent?
Section titled “Why is DELETE Idempotent?”💡 Whether you cancel a reservation once or multiple times, the end result is the same – no reservation exists.
HEAD: Get the same information as GET, but without the response body.
Section titled “HEAD: Get the same information as GET, but without the response body.”Like asking if they have a table available without getting the full details about the table, menu, or prices. You just want to know if it exists.
Key Characteristics
Section titled “Key Characteristics”- SAFE: Never modifies server data
- IDEMPOTENT: Multiple calls have the same effect
- NO RESPONSE BODY: Only headers are returned
- SAME HEADERS AS GET: Includes content type, length, last modified, etc.
When to Use HEAD?
Section titled “When to Use HEAD?”💡 Perfect for checking if content exists, getting file sizes, or checking last-modified dates without downloading large files.
OPTIONS: Find out what HTTP methods are supported for a specific endpoint.
Section titled “OPTIONS: Find out what HTTP methods are supported for a specific endpoint.”Like asking what services are available – can you make reservations? Take-out orders? Catering requests? The restaurant tells you all the ways you can interact with them.
Key Characteristics
Section titled “Key Characteristics”- SAFE: Never modifies server data
- IDEMPOTENT: Multiple calls have the same effect
- NO REQUEST BODY: Just asks about capabilities
- RETURNS ALLOWED METHODS: Lists supported HTTP methods
When to Use OPTIONS?
💡 Mainly for CORS (Cross-Origin Resource Sharing) requests and API discovery.
Understanding Safety and Idempotency
Section titled “Understanding Safety and Idempotency”Safe Methods
Section titled “Safe Methods”Safe methods don’t modify anything on the server. They’re read-only operations.
- Safe: GET, HEAD, OPTIONS
- Unsafe: POST, PUT, PATCH, DELETE
Think of safe methods as “looking but not touching” – you can do them without worrying about changing anything.
Idempotent Methods
Section titled “Idempotent Methods”Idempotent methods produce the same result when called multiple times.
- Idempotent: GET, PUT, DELETE, HEAD, OPTIONS
- Not Idempotent: POST, PATCH
Think of idempotent methods as operations where “doing it again doesn’t change the outcome.”
Choosing the Right Method
Section titled “Choosing the Right Method”Decision Framework
Section titled “Decision Framework”Reading data? → Use GET
Creating something new? → Use POST
Replacing something completely? → Use PUT
Updating specific fields? → Use PATCH
Removing something? → Use DELETE
Just checking if something exists? → Use HEAD
Discovering available actions? → Use OPTIONS
Common Decision Points
Section titled “Common Decision Points”POST vs PUT for Creation:
- Use POST when the server assigns the ID
- Use PUT when the client specifies the ID
PUT vs PATCH for Updates:
- Use PUT when replacing the entire resource
- Use PATCH when updating specific fields
GET vs HEAD:
- Use GET when you need the content
- Use HEAD when you only need metadata
Common Mistakes to Avoid
Section titled “Common Mistakes to Avoid”Using GET for Actions
Section titled “Using GET for Actions”❌ Wrong:
GET /api/articles/123/delete
⚠️ Why it’s wrong: GET requests should never change server state. Using GET for actions that modify data violates HTTP standards, creates security risks (as URLs can be cached or accidentally triggered), and confuses other developers.
✅ Right:
DELETE /api/articles/123
Using POST for Everything
Section titled “Using POST for Everything”❌ Wrong:
POST /api/getArticles
⚠️ Why it’s wrong: Using POST for read operations prevents caching, requires request bodies when unnecessary, and breaks RESTful conventions. This makes your API harder to understand and less efficient.
✅ Right:
GET /api/articles
Confusing PUT and PATCH
Section titled “Confusing PUT and PATCH”❌ Wrong: Using PUT to update just one field (overwrites others)
⚠️ Why it’s wrong: Using PUT for partial updates can unintentionally delete data since PUT replaces the entire resource. Any fields not included in the request will be removed, potentially causing data loss.
✅ Right: Use PATCH for partial updates, PUT for complete replacement
Ignoring Idempotency
Section titled “Ignoring Idempotency”❌ Wrong: Using POST for updates (creates duplicates)
⚠️ Why it’s wrong: POST is not idempotent, meaning if a client retries a failed request, it could create multiple resources or apply the same update multiple times. This leads to duplicated data and inconsistent states, especially during network issues.
✅ Right: Use PUT or PATCH for updates
The Bottom Line
Section titled “The Bottom Line”HTTP methods are the verbs that define what action you want to perform on a resource. While they have specific semantics, safety guarantees, and idempotency properties that affect how servers handle requests, the real-world application of these principles isn’t always straightforward.
In practice, you’ll encounter edge cases where the “correct” method isn’t obvious—like batch operations, complex state transitions, or legacy system integrations.
Understanding these methods thoroughly helps you build more reliable applications, follow web standards correctly, and make informed decisions when facing these ambiguities. As your applications grow in complexity, this foundation becomes increasingly valuable.
Choose your HTTP methods thoughtfully—they’re more than technical details. They represent important contracts between your application and the servers it communicates with, and mastering them is essential as you advance to building more sophisticated systems.
For further reading, check out these official resources.
- MDN Web Docs – HTTP Request Methods - A very clear, practical reference with examples: MDN: HTTP request methods
- RFC 7231 – Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content- The actual specification. Great if you want precise definitions: IETF RFC 7231
Continue Your API Journey
Section titled “Continue Your API Journey”Ready to dive deeper?
- What are HTTP Status Codes? - Understand how APIs communicate success, errors, and other important information through standardized status codes.
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When should I use PUT vs PATCH?
Use PUT to replace an entire resource (requires sending all fields). Use PATCH for partial updates (send only changed fields). PATCH is more bandwidth-efficient for large resources.
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Is it okay to use POST for everything?
No. Using the correct HTTP method makes your API predictable, cacheable, and follows REST principles. GET for reads, POST for creates, PUT/PATCH for updates, DELETE for removals.
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Can I use DELETE with a request body?
While HTTP allows it, many frameworks and proxies don’t support request bodies in DELETE. Use URL parameters or headers for DELETE requests instead.
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What’s an idempotent HTTP method?
An idempotent method produces the same result no matter how many times you call it. GET, PUT, and DELETE are idempotent. POST and PATCH are not.
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Why does my GET request fail when I send data in the body?
GET requests should not have request bodies per HTTP specification. Use query parameters instead:
GET /api/users?status=active.