204 Status Code (No Content): What is it, How Does it Work & When to Use it?

The 204 Status Code is one of the many HTTP status codes that keep the internet running smoothly. It signifies that the server has successfully completed the request, much like the 200 OK status code. However, with the 204 No Content status, there is no additional content in the response body to show to the user. This status code is used for operations that happen behind the scenes.

What exactly does the 204 No Content status mean? How and when should you use it? What potential issues might arise? We’ll answer these questions here, so read on.

In other words – the server did what was asked, but there’s nothing new or a specific target resource to show. This is useful for actions like form submissions or AJAX requests where the client doesn’t need to navigate away from the current page.

The HTTP response includes entity headers but no body content. That makes it clear that no further information is required. Practically, the response starts with the HTTP status, headers follow up, and it ends after the first empty line by default.

How does the HTTP 204 Status Code Work?

Have you ever sent a request online and noticed nothing changed on your screen? That’s the work of the HTTP 204 status. It tells you that the server accepted your request and handled it perfectly, but there’s no new info to show.

Let’s break down how this works and why it’s so useful for keeping things running smoothly without unnecessary updates.

Here’s a breakdown of the graphic above:

1. The client application (e.g., a web browser or an API client) sends a request to the server.
2. The server receives the request and processes it. That includes updating a database record or deleting a file.
3. Once the server successfully processes the requested action, it prepares a response. If the action does not require any new information to be sent back, the server opts for a 204 status code.
4. The server sends back a response with the 204 status code, indicating that the request was successful, but there is no content to return. The response will include the status line and HTTP headers but no body content.
5. The user-agent receives the 204 No Content response. Since there is no content, the client does not need to update the current page or display any new information.
6. The client remains on the same page or continues its current operation without any interruption.

What is the difference between 200 and 204 responses?

The HTTP 200 and 204 status codes both signal that a request was successfully processed, but they do so in different ways.

A 200 Status Code is known as “OK.” This means the server handled the request and is sending back the requested content, like a webpage or data. This is the go-to response for most successful requests where the client needs to receive some kind of data.

On the other hand, the 204 No Content also means the request was processed successfully, but there’s no new content response to send back. Think of it as the server giving a valid response without saying anything.

This is handy for actions where the user agent doesn’t need to update the current page, like when you submit a form or make an AJAX request. The client stays put, and everything continues smoothly without any unnecessary data transfer.

204 Response Payload Body and Cacheability

To understand how the HTTP 204 status code works, we must elaborate on two key points: the response payload body and cacheability. These concepts promote website speed and efficiency.

Let’s examine them in more detail.

The Concept of Response Payload Body (Definition)

The payload body is the part of an HTTP response containing the actual data sent back by the server (text, images, etc.). But with a 204 status, things are a bit different.

With the 204 status code, the server informs the user agent that there is no content to return in the response body. However, the response will still have headers. These give extra information, like the date, server details, and connection status.

This is practical for actions where the client doesn’t need to update the page or show new information, like when you submit a form.

How Cacheability Applies to 204 Status Code

Cacheability refers to the ability to store responses so they can be reused later. This reduces the need to ask the server for the same information again.

Since a 204 response has no content, there’s nothing to store. But the headers can still be cached. The server can include special instructions in the HTTP headers to tell the client how to handle caching.

For example, Cache-Control: no-store means don’t store this response. While Cache-Control: max-age=3600 means store it for one hour.

Here is an example of a 204 response with cache-control headers:

HTTP/1.1 204 No Content

Date: Mon, 25 Sep 2023 12:34:56 GMT

Server: Apache/2.4.41 (Ubuntu)

Cache-Control: max-age=3600

Connection: keep-alive

This way, the client can quickly determine that there is no additional data without asking the server again, which speeds things up.

HTTP 204 Status Code Examples

The HTTP 204 status code is flexible and can be applied to improve web interactions in various scenarios.

Below, we’ll touch on just a few real-life examples where the 204 status code is commonly used.

• AJAX Requests

A common example of the 204 usage is some AJAX Requests. When you change your user name on a website, it sends an AJAX request to the server to update your profile. The server processes the action request and sends a 204 response to confirm it has successfully fulfilled it. Then, the user agent (your browser) will present the new user name without reloading the page or sending back any additional information.

• Form Submissions

Another frequently seen example is the use of a 204 response in form submission. You hit submit when you are ready filling out an online survey or feedback form. That sends a POST Request to the server, which returns a 204 response for confirmation. The form remains on the same page, possibly showing a “Thank you” message via JavaScript.

• Automated Data Transfers

Let’s say you are looking at a weather update service website. The weather service automatically sends temperature data to a central server every hour using a POST Request. The server processes the data and returns a 204 status code to acknowledge the receipt without sending back any additional information.

• Distributed Version Control Systems (DVCS)

If we look into GITHub, we can see another example of the 204 response code usage. When a developer pushes changes to a remote repository, the server processes the changes. After the server has successfully fulfilled the request, it can return a 204 status to acknowledge the push without returning any additional data.

Here is a simple example of the 204 Status Code and header fields in the Network tab of the Chrome Developer Console:

HTTP/1.1 204 No Content

Date: Mon, 25 Sep 2023 12:34:56 GMT

Server: Apache/2.4.41 (Ubuntu)

Connection: keep-alive

In this example, the response includes the status line (HTTP/1.1 204 No Content) and header fields for Date, Server, and Connection, but there is no body content.

When to Use a 204 Status Code?

The HTTP 204 No Content status code is a useful tool for web developers and API designers. This specific status from the HTTP Status Codes indicates that the server has successfully received the request but does not return any content. This status code is beneficial in scenarios where the client does not need to update the current user resource page or display new information.

The Benefits of a 204 Status Code

Here, we’ll look into the benefits and potential pitfalls of implementing the 204 No Content status within your infrastructure.

Efficiency in data transmission

One of the primary benefits of using HTTP status 204 is efficiency in data transmission. The server conserves bandwidth and reduces the amount of data transmitted over the network by not sending a message body. This is particularly useful in applications that expect automated data transfers, like in real-time data updates or background synchronization tasks.

Clarity in client-server communication

The 204 status code provides clarity in client-server communication. It clearly indicates to the client that there is no new information to process or display. This can help avoid confusion and ensure that the client understands that the request was successful but no additional data is needed.

Performance improvements

Reducing the amount of data sent can lead to faster response times, which is crucial for performance-sensitive applications. With a 204 No Content response, the server can quickly acknowledge the request without the overhead of generating and transmitting a response body. This can result in a more responsive and efficient application, particularly in scenarios where low latency is essential.

Potential Pitfalls of the 204 Response Code

In this part, we’ll overview some of the potential issues you may encounter with the 204 No Content status.

Misuse of 204 status code

While the 204 status code is useful, it can be misused if not applied correctly. For example, using a 204 status code when the client expects a response body can lead to confusion and errors. It’s important to ensure that the client does not require any additional information before deciding to use a 204 status code. Misuse can result in incomplete transactions or a lack of necessary feedback to the client.

Client-side handling of 204 responses

Another potential pitfall is the client-side handling of 204 responses. Not all clients may be prepared to handle a 204 status code correctly. Developers need to ensure that their client applications can properly interpret and respond to a 204 status code. This includes updating the client-side logic to recognize that a 204 response means the request was successful, but no further action is needed. Failure to handle 204 responses correctly can lead to unexpected behavior or errors in the application.

204 Status Code Impact on SEO

Search engines like Google rely on content to index and rank pages. A 204 status code means there is no content for the search engine to index, which can result in the page not being included in search results. This is not necessarily an issue if the page is not intended to be indexed, but it is something to be aware of.

Therefore, overusing the HTTP 204 status may inefficiently use the crawl budget for non-indexable pages. For pages you want to be indexed and ranked, ensure they return a 200 OK status code and includes content.

What is the Browser Compatibility of the 204 HTTP Status Code?

HTTP 204 is fully supported by most modern browsers. This widespread compatibility makes it a reliable choice for scenarios where the server needs to acknowledge a successful request without returning any content.

For better clarity and assimilation, we’ll use the table below.

Conclusion

The HTTP 204 status code helps make web applications faster by handling requests without sending extra data. It saves bandwidth, makes communication clear, and speeds up response times. But, it’s important to use it correctly to avoid issues, especially with SEO and how clients handle it. Knowing when to use the 204 status code can improve user experience and make automated data transfers smoother.

HTTP 204 Status Code FAQs

Is 204 a success or failure?

The HTTP 204 status code is definitely a success. It indicates that the server has successfully processed the request but has no content to return. If there were any issues or errors during the processing of the request, the server would return a different status code. Such status codes can be a 4xx code for client errors (400, 401, 404) or a 5xx code for server errors (500, 503, 504). So, if you see a 204 status code, you can be confident that the request was handled successfully.

How do I Fix my 204 Status Code?

If you are experiencing issues with your 204 No Content status, you must check if your request is correct. Also, verify that your server is properly configured and that the user agent side code is compatible with 204 responses.

What is the 204 Status Code in Google Analytics?

In Google Analytics 4, a 204 status code means a tracking request was received and processed, but no content was returned. It’s used for tracking pixels, which collect data without affecting the user experience. This code keeps data transmission efficient and doesn’t reload the page or show any content, it simply records the user’s actions. Thanks to that, Google Analytics can gather data without slowing down the website.

When to use HTTP Status Code 204 vs 404?

Use a 204 status code when the server successfully processes a request but has no content to return. It’s great for actions like form submissions or updates where no new page content is needed. Use a 404 status code when the requested resource is not found on the server. This tells the client that the page or resource they are looking for doesn’t exist.

What is a 204 Code DELETE?

A 204 code with DELETE means the server successfully processed a DELETE request but has no content to return. It’s used to confirm that the resource was deleted without sending any additional data. This keeps the response efficient and clear. The client knows the delete action was successful without needing more information.