Differences Between 204 and 404 Codes, Examples of Using and Resolving

Understanding HTTP status codes is crucial for effective communication between the server and clients when managing a website or developing an application. This article will delve into the differences between HTTP status codes 204 and 404, discussing their meanings, appropriate use cases, best practices, and impact on SEO.

The primary difference between HTTP status codes 204 and 404 lies in their meaning and the context in which they are used:

• 204 No Content: This status code signifies that the server has successfully processed the request but has no content to send back. Unlike a 404, which indicates an error or missing resource, a 204 response is used when the request is successful, but there is no need to return any data to the client.

• 404 Not Found: This status code indicates that the server cannot find the requested resource. It means that the URL provided does not point to any valid page or resource on the server. A 404 response is typically used when a user or client attempts to access a page that does not exist.

Understanding the impact of HTTP status codes on SEO is essential for web developers and SEO professionals. HTTP 204 No Content and 404 Not Found status codes play distinct roles in web interactions and influence search engine optimization differently. Here, we explore their impacts.

204 No Content

The 204 status code indicates that the server has successfully processed the request but has no content to send back. This status code has a neutral impact on SEO.

• Search Engine Crawling: Since a 204 response signals a successful request without content, it doesn’t affect the indexing or ranking of pages. Search engines recognize that no content change is needed, which helps maintain efficiency.
• User Experience: 204 responses efficiently manage updates or confirmations without reloading content, enhancing user experience and performance. This efficiency, while not directly affecting SEO, contributes to smoother user interaction.

404 Not Found

The 404 status code informs that the requested resource is unavailable or does not exist. Its impact on SEO can be significant.

• Negative Impact on Rankings: Frequent 404 errors can lead search engines to perceive a website as poorly maintained. This perception can result in lower rankings since search engines aim to direct users to reliable sources.
• User Experience: A high number of 404 errors can frustrate users, leading to increased bounce rates and reduced engagement. Poor user experience can indirectly affect SEO by signaling to search engines that the site may not be valuable to users.
• Link Equity Loss: Links pointing to 404 pages do not pass any link equity. This loss can diminish the SEO value of those links that would otherwise contribute to the site. Redirecting broken links to relevant pages can help retain link equity.

204 Status Code:

The HTTP 204 No Content status code is an integral part of web development, mainly when dealing with operations that require no content to be returned to the client. This status code indicates that the server has successfully processed the request but has no content to send back. The 204 No Content status code is a valuable tool for optimizing web communication by acknowledging successful requests without sending unnecessary data. Its use helps streamline interactions between the client and server.

Below are some practical examples and use cases of the 204 status code.

1. Updating User Settings
When a user updates their profile settings, such as changing their email preferences or notification settings, the server processes this request without reloading the page or displaying any new content. In this scenario, returning a 204 status code is appropriate because it confirms the success of the request without requiring any additional information to be sent to the client.

2. AJAX Requests in Web Applications
In modern web applications, AJAX (Asynchronous JavaScript and XML) requests are frequently used to update parts of a web page without reloading the entire page. When an AJAX request is made to save user input or perform an action that does not necessitate a change in the displayed content, a 204 status code is suitable. It indicates the successful completion of the request while minimizing the amount of data transmitted over the network.

3. API Endpoints for Logging Out Users
API endpoints designed to handle user logouts often do not need to return any content upon successful execution. When a user logs out, the server can invalidate the session or remove the authentication token and respond with a 204 status code. This signifies that the logout was successful without sending back any data.

4. Form Submissions
When users submit forms that do not require a page refresh or an update to the user interface, such as updating background preferences or toggling settings, the server can respond with a 204 status code. This approach confirms the form submission was processed correctly without returning unnecessary content.

5. Polling Mechanisms
In applications that implement polling mechanisms to check for updates or new data, the server might return a 204 status code when there is no new information to provide. This can help optimize network usage by reducing the data sent back and forth when no updates are available.

6. Background Task Completion
When background tasks or processes are executed on the server, and the client needs confirmation of completion without any accompanying data, the server can respond with a 204 status code. This is particularly useful for asynchronous operations where the client only needs to know that the task was successfully executed.

404 Error Code:

The HTTP 404 Not Found status code is crucial in web development and server management, indicating that the server cannot locate the requested resource. This status code informs users and search engines that the requested URL does not point to a valid page or resource.

Here are some practical examples and use cases of the 404 error code.

1. Non-Existent Pages
A 404 error is most commonly used when a user attempts to access a page that does not exist. This can occur due to mistyped URLs, outdated links, or deleted pages. Implementing a 404 status code in these scenarios helps inform users that the resource is unavailable, allowing them to navigate elsewhere.

2. Broken Links
Broken links, also known as dead links, occur when hyperlinks point to URLs that no longer exist. When users or search engine bots encounter these links, the server should return a 404 error. This helps maintain a clean and user-friendly website by alerting administrators to fix or remove broken links.

3. Moved or Deleted content
When content is moved to a new URL or deleted without setting up a proper redirect, the old URL should return a 404 error. This informs users and search engines that the content previously located at that URL is no longer available. Setting up a 301 redirect for moved content can help preserve SEO value and user experience.

4. Incorrect URL Mapping
In web applications, incorrect URL mapping can lead to requests for non-existent endpoints. For instance, if an application expects specific URL parameters but receives an unexpected format, it should return a 404 error to indicate the requested resource does not exist.

5. API Endpoints
A 404 error can indicate that the requested endpoint or resource does not exist for RESTful APIs. This is useful for guiding developers using the API, helping them understand that they may have used an incorrect endpoint or resource identifier.

6. Typo in URL
A common user error is typing an incorrect URL. When this happens, the server should return a 404 error, indicating that the resource cannot be found. This helps users quickly realize their mistake and try again with the correct URL.

The 404 Not Found status code maintains clear communication between the server, users, and search engines. It serves multiple purposes, from indicating non-existent pages and broken links to handling incorrect URL mappings and API endpoints. By appropriately using the 404 error code, developers can enhance user experience and ensure proper site maintenance.

Understanding and correctly implementing HTTP status codes 204 and 404 is crucial for maintaining effective communication between the server and clients, as well as for optimizing SEO performance.

Atomseo Broken Links Checker is an invaluable tool for effectively monitoring and managing these status codes. It allows you to track various errors and status codes, including 204 and 404, ensuring that your website remains in optimal condition. Additionally, Atomseo Broken Links Checker allows you to check up to 1500 links per day for free, making it a convenient and cost-effective solution for maintaining your site's health.