Essential HTTP Status Codes Every Web Developer Should Know
Tags: webdev, beginners, http, react
Published: 2024-06-20 02:21:39

Understanding HTTP status codes is crucial for web developers. These codes provide insight into the status of a request made to a server, helping you diagnose and troubleshoot issues effectively. Here’s a comprehensive guide to 18 essential HTTP status codes that you need to know.

## 1. 200 OK
**Request Succeeded**

The 200 status code indicates that the request has succeeded. The server has successfully processed the request, and the result is returned in the response.

![200](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/pwh64tijl90edabhy5gu.jpg)

## 2. 201 Created
**Resource Created**

The 201 status code signifies that the request has been fulfilled and a new resource has been created as a result. This is typically the response after a POST request.

![201](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ot04b75t7f232go1w53g.jpg)

## 3. 202 Accepted
**Accepted Request**

The 202 status code means that the request has been accepted for processing, but the processing has not been completed. This is often used for asynchronous operations.

![202](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/xz5xt08gll5nsx9cnm5i.jpg)
## 4. 204 No Content
**No Content**

The 204 status code indicates that the server has successfully processed the request, but there is no content to send in the response. This is common for DELETE requests.

![204](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/mz0fdrov4nqcyu7yhsmu.jpg)
## 5. 301 Moved Permanently
**Resource Moved Permanently**

The 301 status code tells the client that the resource requested has been permanently moved to a new URL. The client should use the new URL for future requests.

![301](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/eul9lo5ytcnu6idu9m46.jpg)
## 6. 302 Found
**Temporarily Moved**

The 302 status code indicates that the resource requested is temporarily located at a different URL. The client should continue to use the original URL for future requests.

![302](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/gpp0h5zkl0jrkogca5ev.jpg)
## 7. 304 Not Modified
**Not Modified**

The 304 status code means that the resource has not been modified since the last request. The client can use the cached version of the resource.

![304](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ootswm9sjgovxiqbhv09.jpg)
## 8. 400 Bad Request
**Bad Request Error**

The 400 status code indicates that the server could not understand the request due to invalid syntax. This is a client-side error.

![400](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/xtzgy8p5g02fa84h36zj.jpg)
## 9. 401 Unauthorized
**Needs Authentication**

The 401 status code means that the request requires user authentication. The client must authenticate itself to get the requested response.

![401](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/371pyg8vcru1a0bovui7.jpg)
## 10. 403 Forbidden
**Access Forbidden**

The 403 status code indicates that the server understands the request but refuses to authorize it. This is often due to insufficient permissions.

![403](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/1k17j4daj6f3v8zqz8r3.jpg)
## 11. 404 Not Found
**Resource Not Found**

The 404 status code means that the server cannot find the requested resource. This is a common error when the URL is incorrect or the resource does not exist.

![404](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/kw6tdu8ut01fqf74n9fj.jpg)
## 12. 405 Method Not Allowed
**Method Not Allowed**

The 405 status code indicates that the request method is not supported for the requested resource. For example, using a POST method on a read-only resource.

![405](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/olnwrgj9462wbsdplm1x.jpg)
## 13. 408 Request Timeout
**Request Timed Out**

The 408 status code means that the server timed out waiting for the request. This can happen if the request takes too long to complete.

![408](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/l3fmc15qy2u9s73gj28q.jpg)
## 14. 500 Internal Server Error
**Server Error**

The 500 status code indicates that the server encountered an unexpected condition that prevented it from fulfilling the request. This is a generic server error message.

![500](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/4y35nuf6794hc551c33s.jpg)
## 15. 501 Not Implemented
**Not Implemented**

The 501 status code means that the server does not support the functionality required to fulfill the request. This indicates that the server cannot recognize the request method.

![501](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/qjm4636dcbdbwmy1y2cm.jpg)
## 16. 502 Bad Gateway
**Bad Gateway Error**

The 502 status code indicates that the server, while acting as a gateway or proxy, received an invalid response from the upstream server.

![502](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/4l703u5vg6d0k50j8zd2.jpg)
## 17. 503 Service Unavailable
**Service Unavailable**

The 503 status code means that the server is currently unable to handle the request due to temporary overloading or maintenance of the server.

![503](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/57chddnjd9skd6mu9q92.jpg)
## 18. 504 Gateway Timeout
**Gateway Timeout**

The 504 status code indicates that the server, while acting as a gateway or proxy, did not receive a timely response from the upstream server. This typically happens when the server is down or not responding.

![504](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/84ijmomt2n102lzbqoek.jpg)
## Conclusion

HTTP status codes are vital for understanding the outcome of a request and diagnosing issues in web development. Familiarizing yourself with these codes will help you quickly identify and resolve problems, ensuring a smoother development process and a better user experience.

By mastering these essential HTTP status codes, you can enhance your ability to debug issues, optimize your server-client interactions, and improve the overall functionality of your web applications.