HTTP Status Codes Explained Simply

HTTP Status Code Categories (1xx to 5xx)

Status codes are grouped by their first digit:

• 1xx (Informational): The request was received and is being processed. You rarely see these.
• 2xx (Success): Everything worked. 200 OK is the most common.
• 3xx (Redirection): The resource moved somewhere else. Your browser follows the redirect automatically.
• 4xx (Client Error): Something is wrong with the request. The problem is on your end.
• 5xx (Server Error): The server failed to handle a valid request. The problem is on the server's end.

Knowing the category tells you immediately where the problem is. 4xx means check your request. 5xx means the server has an issue.

Most Common HTTP Status Codes

These are the status codes you'll see 90% of the time:

• 200 OK: The request succeeded. For GET requests, the response contains the data you asked for.
• 201 Created: A new resource was created successfully (common after POST requests).
• 301 Moved Permanently: The URL changed permanently. Update your links and bookmarks.
• 302 Found: Temporary redirect. The resource is at a different URL for now.
• 400 Bad Request: The server can't understand your request. Check your syntax, headers, or body.
• 401 Unauthorized: You need to log in first. Send valid authentication credentials.
• 403 Forbidden: You're logged in but don't have permission to access this resource.
• 404 Not Found: The URL doesn't exist. Check for typos in the URL.
• 500 Internal Server Error: Something broke on the server. It's not your fault.
• 502 Bad Gateway: A server acting as a gateway got a bad response from another server.
• 503 Service Unavailable: The server is temporarily down, usually for maintenance or overload.

How to Fix Common HTTP Error Codes

When you hit an error, here's what to do:

400 Bad Request: Check your request body for invalid JSON, missing required fields, or wrong data types. Validate your payload against the API docs.

401 Unauthorized: Your auth token is missing, expired, or invalid. Get a new token and include it in the Authorization header.

403 Forbidden: Your account doesn't have permission. Check your role or API key scope. Contact the admin if you need access.

404 Not Found: Double-check the URL for typos. Make sure the resource exists. The endpoint might have changed in a newer API version.

429 Too Many Requests: You're hitting the rate limit. Slow down your requests. Check for a Retry-After header that tells you when to try again.

500 Internal Server Error: This is a server-side bug. If it's your server, check the error logs. If it's someone else's API, report the issue and try again later.

HTTP Status Codes for API Development

If you're building an API, use the right status codes in your responses:

• Return 200 for successful GET/PUT/PATCH requests
• Return 201 for successful POST requests that create a resource
• Return 204 No Content for successful DELETE requests
• Return 400 when the client sends bad data
• Return 401 when authentication is missing
• Return 403 when the user is authenticated but not authorized
• Return 404 when the resource doesn't exist
• Return 409 Conflict for duplicate entries or version conflicts
• Return 422 Unprocessable Entity for validation errors

Using correct status codes makes your API predictable. Clients can handle errors automatically based on the code without parsing error messages.

How to Do It: Step-by-Step

1. 1

   Go to the HTTP Status Codes reference at dotsapps.com.

2. 2

   Search for the specific status code you received.

3. 3

   Read the plain-English explanation of what it means.

4. 4

   Follow the suggested fix for error codes.

5. 5

   Bookmark the page for quick future reference.

Frequently Asked Questions

Related Tools You Might Like