🌐 HTTP Status Code Quick Guide

⚡ Quick Dive

Overview & Key Takeaways

HTTP status codes are issued by a server in response to a client's request. They indicate whether a request has been successfully completed or if errors occurred.

## ✅ 2xx – Success

- **200 OK**: Standard response for successful GET, PUT, PATCH, or DELETE.
- **201 Created**: Resource has been successfully created (e.g., POST).
- **202 Accepted**: Request accepted for processing but not completed yet.
- **204 No Content**: Success, but no content to return (e.g., after DELETE).

## 🔁 3xx – 

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## 📖 Extended Guide

HTTP status codes are issued by a server in response to a client's request. They indicate whether a request has been successfully completed or if errors occurred.

✅ 2xx – Success

  • 200 OK: Standard response for successful GET, PUT, PATCH, or DELETE.
  • 201 Created: Resource has been successfully created (e.g., POST).
  • 202 Accepted: Request accepted for processing but not completed yet.
  • 204 No Content: Success, but no content to return (e.g., after DELETE).

🔁 3xx – Redirection

  • 301 Moved Permanently: Resource has permanently moved to a new URL.
  • 302 Found: Temporary redirect.
  • 304 Not Modified: Cached version is still valid (used with ETags).

❗ 4xx – Client Errors

  • 400 Bad Request: Request is malformed (e.g., invalid JSON, missing params).
  • 401 Unauthorized: Authentication required or failed.
  • 403 Forbidden: Authenticated, but not allowed to access resource.
  • 404 Not Found: Resource does not exist.
  • 405 Method Not Allowed: HTTP method not supported for this resource.
  • 409 Conflict: Request conflicts with server state (e.g., duplicate resource).
  • 422 Unprocessable Entity: Valid request but semantic error (e.g., validation failed).
  • 429 Too Many Requests: Rate limit exceeded.

💥 5xx – Server Errors

  • 500 Internal Server Error: Generic server error.
  • 502 Bad Gateway: Invalid response from upstream server.
  • 503 Service Unavailable: Server is temporarily unavailable (e.g., overloaded).
  • 504 Gateway Timeout: Upstream server didn't respond in time.

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## 🧠 Tips

- Use **200** for successful GET, **201** for successful POST.
- **204** is ideal for DELETE or successful updates without a body.
- Avoid exposing sensitive info in **500** error messages.
- Rate limit APIs and use **429** with a `Retry-After` header.
- Validate inputs and return **400** or **422** with clear messages.
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