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HTTP 204 Response Status Code Guide: What is it, Usage, Methods

May 10 2024 by Oskay Günaçar

What is HTTP 204 Status Code?

The HTTP 204 status code is called "No Content." It is used by a server to indicate that the request was successfully processed, but there is no content to return. This status is often used in response to a successful request where the client does not need to navigate away from its current page or update its current content. For example, it might be used after a form submission that doesn't result in a page change, to confirm that the submission was successful without altering the current display on the user's browser.

Importance of the HTTP 204 Status Code in SEO

The HTTP 204 status code, which indicates "No Content," has some specific uses in the context of SEO (Search Engine Optimization), even though it might not seem directly relevant at first glance. Here’s why it can be important:

  1. User Experience (UX): While HTTP 204 itself doesn't directly affect SEO, it can indirectly influence user experience. By using this status code appropriately (e.g., in response to AJAX requests that do not require a page reload), websites can offer smoother and more responsive interactions. Enhancing user experience is a key factor in SEO, as it leads to higher engagement, longer session durations, and potentially better conversion rates.

  2. Efficient Interaction Handling: When a site needs to handle background data transactions without affecting what the user sees, HTTP 204 can be the right tool. For example, after a user action like voting or form submission where no new content needs to be displayed, a 204 status code can be sent. This efficient handling can improve site performance and user satisfaction, factors that search engines consider.

  3. Reduced Server Load: By responding with no content, the server minimizes the amount of data sent over the network. This can reduce server load and page load times, particularly on dynamic sites that process many such requests. Faster page loads are a positive signal for search engines.

  4. Avoiding Unnecessary Redirects: Sometimes, to keep the user on the same page after an action, developers might use redirects, which can unnecessarily complicate the user journey and increase load times. By using HTTP 204, developers can avoid such redirects, maintaining cleaner, faster, and more SEO-friendly site navigation.

  5. Signals for Bots and Crawlers: Utilizing HTTP 204 correctly helps web crawlers understand that certain requests do not result in new content that needs indexing. This clarity can help search engines more effectively understand and index a site, avoiding wasted resources on both ends.

Although HTTP 204's direct impact on SEO might be minimal, its proper use can contribute to a better structured and more efficient website, which is ultimately beneficial for SEO.

How to Use 204 HTTP Status Code for a Website?

Using the HTTP 204 status code effectively requires understanding when it's appropriate to use it and how to implement it in your server-side code. Here’s a step-by-step guide on how to use the HTTP 204 status code for a website:

1. Identify Appropriate Use Cases

The HTTP 204 status code should be used in situations where:

  • A request has been successfully processed.
  • There's no need to send any data in the response.
  • The client should stay on the same page without reloading or navigating away.

Common scenarios include:

  • AJAX requests where the server's response does not require updating the content of the current page.
  • Form submissions where the result does not require displaying new or updated information.
  • API calls that perform actions (like updating a database) without needing to return data to the client.

2. Implement in Server-Side Code

Depending on your server-side programming language, the implementation will vary. Here are examples for a few common frameworks and languages:

Node.js (Express)

app.post('/api/update-data', (req, res) => {
    // Code to process the request
    // ...
    res.status(204).send(); // Sends a 204 No Content response
});

Python (Flask)

from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/api/update-data', methods=['POST'])
def update_data():
    # Code to process the request
    # ...
    return '', 204  # Return a 204 No Content response

PHP

<?php
// Assuming the request is processed here
http_response_code(204); // Set the HTTP status code to 204
exit(); // Stop the script
?>

 

3. Ensure Client-Side Handling

Make sure that your client-side code (e.g., JavaScript running in the browser) handles the 204 status code appropriately. Since 204 responses do not include any content, your client-side scripts should not expect any data to process. Instead, they might simply acknowledge the success of the operation or update the UI to reflect the changes made (without relying on response data).

4. Test Your Implementation

Testing is crucial to ensure that the 204 status code is being used correctly:

  • Use tools like Postman or cURL to make requests to your server and verify that it responds with a 204 status when expected.
  • Check that the client-side application behaves correctly when receiving a 204 response, maintaining the current state without trying to process non-existent response data.

5. Monitor and Optimize

After deploying changes to your production environment, monitor the application to ensure that the use of HTTP 204 is achieving the desired outcomes, such as improved performance or user experience. Adjust your implementation based on real-world usage and feedback.

By following these steps, you can effectively use the HTTP 204 status code to enhance your website's responsiveness and efficiency.

How to Check HTTP 204 Status Code?

To check for an HTTP 204 status code, you can use various methods depending on your role (developer, tester, or simply a user checking server responses). Here are some common tools and techniques for checking HTTP status codes, including 204 "No Content":

1. Browser Developer Tools

You can use the network analysis feature found in most modern web browsers (like Chrome, Firefox, or Edge) to inspect HTTP responses. Here’s how:

  1. Open Developer Tools: Right-click on a webpage and select "Inspect" or press Ctrl+Shift+I (Windows/Linux) or Cmd+Option+I (Mac).
  2. Go to the Network Tab: This tab records all network activity when you load or interact with the page.
  3. Trigger the Request: Perform the action that triggers the request you want to inspect.
  4. Inspect the Status Code: Look for the request in the list and check the status code column. If it’s properly configured, you'll see "204" for requests that return no content.

2. Command Line Tools

  • cURL: A versatile command-line tool used to transfer data using various network protocols. To check for a 204 status, use:

    curl -I http://example.com/path
    

    This command performs a HEAD request which retrieves the headers. Look for HTTP/1.1 204 No Content in the response.

  • HTTPie: This is a user-friendly HTTP client in the command line. Similar to cURL, you can use it to check headers:

    http --headers HEAD http://example.com/path
    

3. Automated Testing Tools

If you are testing an API or a web application, you might use automated testing frameworks to check HTTP responses:

  • Postman: An application for API testing that provides a user-friendly interface to send requests and inspect responses, including status codes.
  • JUnit (for Java applications) or pytest (for Python applications): These testing frameworks can be used in conjunction with libraries like RestAssured (Java) or Requests (Python) to programmatically check that a server returns a 204 response under the correct conditions.

4. Logging and Monitoring Tools

If you manage a server, you can set up logging to record all responses with their HTTP status codes. Tools like ELK Stack (Elasticsearch, Logstash, Kibana) or Splunk can be configured to monitor and visualize HTTP status codes, including 204 responses, from server logs.

5. Network Monitoring Tools

Network administrators might use tools like Wireshark to capture and analyze network traffic. These tools can filter HTTP responses by status codes and inspect the details of the traffic, including the presence of a 204 status code.

By using these methods, you can effectively check for the HTTP 204 status code across different scenarios, helping ensure your applications handle requests appropriately.

Which HTTP Method is used with HTTP 204 Status Code?

The HTTP 204 status code, which indicates "No Content," can be used with various HTTP methods depending on the context of the request. Here are the most common methods where an HTTP 204 response might be appropriate:

1. POST

  • Use Case: When the server successfully processes a POST request but does not need to return any content. For example, when a form is submitted to update data in a database and no additional information needs to be sent back to the client.
  • Example: Submitting user preferences or form data that updates a configuration without needing to provide a result.

2. PUT

  • Use Case: In response to a PUT request when the server updates an existing resource successfully but doesn't need to send any data back. This might occur when the client already has the updated resource representation and only needs confirmation that the update was successful.
  • Example: Updating a user's profile information where the client already displays the new data entered by the user.

3. DELETE

  • Use Case: After a DELETE request, if the server successfully deletes a resource and no further content needs to be sent back to the client.
  • Example: Removing a specific item from a list, where the client already handles the removal in the user interface.

4. PATCH

  • Use Case: Similar to PUT, PATCH is used for making partial updates to a resource. A 204 response can be sent when these updates are successfully applied without needing to send back the updated resource.
  • Example: Modifying a portion of a resource, like changing a user's email address or settings, where the client already reflects the change.

HTTP 204 can technically be returned in response to any HTTP method if the conditions align: the server successfully processes the request, and there is no additional content to send back to the client. However, it's most commonly associated with the methods listed above, as these often involve modifications to server resources where the confirmation of success is needed but returning the updated resource is not necessary.

What is the Browser Compatibility of HTTP 204 Status Code?

The HTTP 204 status code, "No Content," is widely supported across all modern web browsers. This status code is part of the HTTP/1.1 standard, which has been widely implemented in web browsers for many years. The browsers that support HTTP 204 include:

  • Google Chrome
  • Mozilla Firefox
  • Apple Safari
  • Microsoft Edge
  • Opera

Older browsers, including Internet Explorer versions, also support the HTTP 204 status code. Given its fundamental nature in the HTTP protocol and its long-standing inclusion in the HTTP specification, you can generally expect consistent handling of this status code across all web browsers.

The compatibility of HTTP 204 is particularly important for web developers implementing AJAX operations or API interactions where the server might need to signal that a request was successful without needing to refresh the page or return additional data. The browser's ability to correctly interpret and act on a 204 response helps ensure that web applications function smoothly, maintaining user experience and performance.

Overall, there should be no concerns regarding browser compatibility when using the HTTP 204 status code. If a web application is experiencing issues related to handling this status code, the problem is likely due to the specific implementation or other aspects of the application's code rather than the browser's ability to handle the status code itself.1

Best Practices for Handling HTTP 204

Using the HTTP 204 "No Content" status code effectively requires understanding its intended purpose and implementing it correctly in your server and client-side logic. Here are some best practices for handling HTTP 204 status codes in your applications:

1. Use It for Appropriate Scenarios

Only use HTTP 204 when a request has been successfully processed and there's no need to return any content. Common scenarios include:

  • AJAX Requests: For actions that do not require updating the current page content.
  • Form Submissions: When updating data on the server without needing to provide feedback via new content.
  • RESTful APIs: In response to PUT, PATCH, or DELETE requests where the client does not need new data.

2. Ensure Proper Client Handling

Since the 204 response contains no body, ensure that your client-side code correctly handles these responses without expecting any data:

  • JavaScript: Check the status code before trying to process the response data.
  • Frameworks and Libraries: Configure AJAX or API call settings to handle 204 appropriately, potentially by simply confirming success to the user.

3. Document API Behavior

If you're developing an API that returns HTTP 204 responses, document this clearly in your API documentation. Specify under what conditions a 204 might be returned and what it signifies, so that developers consuming your API can properly handle it in their applications.

4. Do Not Use for Errors

HTTP 204 indicates success. Do not use it to quietly fail or swallow errors. If an error occurs, use the appropriate 4xx or 5xx status codes to signal what went wrong.

5. Optimize Performance

One of the benefits of 204 responses is reduced bandwidth usage since no data is sent. This can be particularly useful for improving the performance of mobile applications or in environments with limited bandwidth.

6. Testing and Validation

Thoroughly test how your application handles HTTP 204 responses:

  • Unit Tests: Write tests to ensure your server returns a 204 status under the correct conditions.
  • Integration Tests: Test how the client and server interact when a 204 response is sent, verifying that the client behaves as expected.
  • End-to-End Tests: Check the full flow from the user's perspective to ensure that the application behaves correctly when a 204 response is received.

7. Graceful Degradation

In environments where clients might not handle HTTP 204 well, consider offering a graceful degradation path. This might involve configuring the server to return a minimal response body instead of none at all if certain conditions are detected.

8. Security Considerations

Always validate and sanitize incoming data before deciding to send a 204 response. Just because no content is returned doesn't mean security practices should be ignored. Ensure that all data handling paths are secure to prevent exploits that might rely on improper handling of these "silent" responses.

By following these best practices, you can ensure that HTTP 204 is used effectively in your web applications, enhancing performance and user experience without sacrificing functionality or security.

Conclusion

The HTTP 204 status code, "No Content," is a powerful tool in the arsenal of web developers and API architects. It effectively communicates the success of an operation without the need for further content delivery, enhancing the efficiency and responsiveness of web interactions. While it may seem simple, its correct implementation can significantly influence user experience, server performance, and overall site functionality.

By adhering to best practices, such as ensuring proper client-side handling, using it in appropriate scenarios, and maintaining robust security measures, developers can leverage HTTP 204 to streamline interactions and reduce unnecessary data transfers. This not only improves the speed and smoothness of web applications but also contributes positively to SEO by enhancing user engagement and satisfaction.

As we continue to push for more efficient and user-friendly web experiences, understanding and utilizing HTTP status codes like 204 become crucial. They are not just technical responses but tools that, when used correctly, can create a more seamless and interactive web environment. Remember, every byte and every second counts in delivering an optimal user experience. With HTTP 204, we have one more technique to ensure our applications are as efficient and responsive as they can be.

Oskay Günaçar
Oskay Günaçar is a Technical SEO expert and backend developer. His main areas of interest are back-end programming, Python, Django, Go, semantic SEO, technical SEO. With more than 5 years of SEO experience, he has held SEO specialist positions at İkiler, Webtures, Boosmart, and Storyly.io companies, and has been involved in numerous projects as an outsourced expert. Through the TechSEOHub website, he aims to share the expertise and experience he has gained from managing and developing (SEO) processes for many successful and large websites in the industry, and to produce content for easy access to accurate and high-quality information.