What are HTTP Status Codes?

HTTP status codes are server responses to requests made by a client, such as a web browser. They indicate whether a request has been successful, and if not, why not.

The are 5 categories are used to group the HTTP responses:

1. Informational responses (100–199)

2. Successful responses (200–299)

3. Redirection messages (300–399)

4. Client error responses (400–499)

5. Server error responses (500–599)

200 – OK

The HTTP response status code 200 is the standard response for successful HTTP requests.

The server responded with “OK” to indicate that the request was successful.

201 – Created

The HTTP response code 201 means that the request is successful and that a new resource has been created.

It is often the case when a new file or directory is uploaded to a web server.

202 – Accepted

It means that the server has accepted the request, but the processing has not been completed.

It is used when the client does not need to wait for the processing to finish before continuing.

204 – No Content

HTTP response status code 204 indicates that the server has successfully processed the request and that there is no content to return.

This is often used when a request is made to update an existing resource, such as when updating a record in a database.

301 – Moved Permanently

It means that the resource you are trying to access has been moved permanently. It is usually the result of a website redesign or change in URL.

302 – Found

The HTTP response status code 302 is similar to status 301, showing that the resource has been moved.

However, unlike status 301, the 302 status code indicates that the redirect is only temporary.

304 – Not Modified

It indicates that previously cached response can be reused, as the requested resource has not been modified.

This can improve performance, as the client does not need to re-download the resource.

400 – Bad request

This HTTP response code means that the server could not understand the request due to invalid syntax.

It is often caused by a client error, such as a malformed URL.

401 – Unauthorized

It indicates that the client is not authorized to access the requested resource.

It is usually due to an invalid or missing authorization header.

403 – Forbidden

It indicates that the client is not authorized to access the requested resource.

It is usually due to a lack of permissions.

404 – Not Found

It is an error message that means the page you are looking for could not be found.

This can be due to several reasons, such as a typo in the URL or the page being moved or deleted.

405 – Method Not Allowed

The HTTP response code 405 indicates that the request method is not allowed for the requested resource.

It is usually due to a problem with the server configuration.

500 – Internal Server Error

Instead of the problem being with pages missing or not found, this status code indicates a problem with the server.

A 500 is a classic server error and will affect access to your site.

503 – Service Unavailable

This could be due to temporarily overloading the server or maintenance of the server.

A 503 status code ensures that the search engines know to come back soon because the page or site is only going to be down for a short time.


Full Stack Developer

About the Author

I’m passionate about web development and design in all its forms, helping small businesses build and improve their online presence. I spend a lot of time learning new techniques and actively helping other people learn web development through a variety of help groups and writing tutorials for my blog about advancements in web design and development.

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