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HTTP 203 Response Status Code Guide: What is it, Usage, Methods

May 09 2024 by Oskay Günaçar

What is HTTP 203 Status Code?

The HTTP 203 status code is defined as "Non-Authoritative Information." It is used to indicate that the returned metadata in the response header is not the definitive set as available from the origin server, but is gathered from a local or a third-party copy. This status code is primarily used for informational purposes and suggests that the response contains modified information that might not match the status of the resource on the original server.

This code is part of the 2xx success codes range, indicating that the request was received and understood, and is being processed. However, it adds a layer of caution about the authenticity or authority of the content of the response.

Importance of the HTTP 203 Status Code in SEO

The HTTP 203 status code, "Non-Authoritative Information," holds limited direct significance in the realm of SEO (Search Engine Optimization), but it can have implications based on how content is managed and served:

  1. Content Authenticity and Trust: Although the HTTP 203 status code isn't commonly used, it signifies that the response content should not be considered definitive. For SEO, the authority and trustworthiness of content are crucial. If content is frequently served with a 203 status, it might raise questions about its authenticity, potentially impacting the trust users and search engines have in the site.

  2. Content Aggregation: If a site is aggregating content from various sources and modifies it before presenting it to users, it might use a 203 status code. This practice should be approached with caution in SEO, as search engines prefer original and authoritative content. Serving modified or aggregated content without clear added value can affect a site's ranking.

  3. Caching and Third-party Services: Sites using third-party services or caching mechanisms might serve content with a 203 status to indicate that the response is not directly from the original source. While this might not impact SEO directly, the effectiveness of caching can influence site speed and user experience, both of which are important SEO factors.

  4. User Experience: Indirectly, if the use of a 203 status code affects how content is perceived or its loading times, it could influence user engagement metrics like bounce rates and time on site. These metrics are used by search engines as indirect signals of a site's quality.

In general, while the HTTP 203 status code itself isn't a significant factor in SEO, the practices around managing and serving content that might lead to its use can impact SEO outcomes. Therefore, it's important for webmasters and SEO strategists to ensure that their content delivery methods enhance the site's credibility, speed, and user experience.

How to Use HTTP 203 Status Code for a Website?

Implementing the HTTP 203 status code, "Non-Authoritative Information," on a website involves careful consideration of when and how it is appropriate to indicate that the information provided may not be from the original source. Here’s a guide on how to effectively use this status code:

1. Determine Appropriate Use Cases

The HTTP 203 status is appropriate in scenarios where the server is serving modified content that does not directly originate from the primary source or is enriched/transformed by an intermediary. Common use cases include:

  • Content aggregation platforms: Sites that compile content from various sources and present an altered or curated version to the user.
  • Proxy servers: Servers that fetch data from the internet, possibly modify it (for example, for compression or format conversion), and then send it to the client.
  • Caching mechanisms: When a cache serves content that might have been transformed or is out of sync with the origin server.

2. Configure Server Responses

Implementing the 203 status code requires configuration at the server level. Here’s a basic example using an Apache server:

  • .htaccess or Apache Configuration File: You can set up conditions under which responses are handled and modified. Here is a pseudocode example:
    Header always set Status "203 Non-Authoritative Information" "expr=%{REQUEST_URI} =~ m|^/aggregated-content/|"
    This configuration sets the response status to 203 for paths that match /aggregated-content/.

3. Modify Application Logic

If your website runs dynamic content managed by server-side scripts (like PHP, Python, Node.js), you might need to explicitly set the HTTP status in your application logic:

  • Example in PHP:
    if ($isContentModified) {
    This code snippet checks if the content has been modified and sets the HTTP response code to 203 accordingly.

4. Test and Validate

Once implemented, thoroughly test the configuration:

  • Testing Tools: Use tools like curl or Postman to verify that the correct status code is returned under the configured conditions.
    curl -I
    Check the headers of the response to ensure the status code is set to 203.

5. Document Usage

Document when and why your website uses the HTTP 203 status code. This is important both for internal reference and to inform users or clients about the nature of the content being served.

6. Monitor and Adjust

Regularly monitor how the status code affects user interaction and site performance. Adjust your use of the status code based on analytics and feedback to optimize the user experience and content authenticity.

Using the HTTP 203 status code can be a transparent way to communicate about the nature of your content, but it should be applied judiciously to avoid any negative implications on user trust and search engine rankings.

How to Check HTTP 203 Status Code?

To check if a web server is returning an HTTP 203 status code, you can use various tools and methods, including web browsers, command-line utilities, and online services. Here’s how to do it with some common tools:

1. Using Curl

Curl is a versatile command-line tool used for transferring data with URLs. It's particularly useful for checking HTTP headers.

  • Command: Run the following command in your terminal or command prompt:
    curl -I
  • Output: Look for the HTTP status code in the headers of the response:
    HTTP/1.1 203 Non-Authoritative Information

2. Using Browser Developer Tools

Most modern web browsers (like Chrome, Firefox, and Edge) have built-in developer tools that can be used to inspect network traffic and view the status codes of requests.

  • Steps:
    1. Open your browser and navigate to the website.
    2. Right-click on the page and select “Inspect” or “Inspect Element” to open the developer tools.
    3. Go to the “Network” tab.
    4. Reload the page to capture the network traffic.
    5. Click on the individual requests to view details, including the status code.

3. Online HTTP Header Checker Tools

There are many online tools available that can fetch a web page and show you the HTTP headers and status codes. Tools like HTTP Status Code Checker, Web Sniffer, or Redbot can be used for this purpose.

  • Process:
    1. Visit an online HTTP checker tool.
    2. Enter the URL of the page you want to check.
    3. Submit the form to view the headers and status code.

4. Using Browser Extensions

Browser extensions like “Live HTTP Headers” (for Chrome) or “HTTP Header Live” (for Firefox) can display the HTTP headers and status codes for all requests made by your browser in real-time.

  • Setup:
    1. Install the extension from the browser’s extension store.
    2. Navigate to the website you want to check.
    3. Use the extension’s interface to view the headers and status codes.

5. Using Postman

Postman is a powerful tool for API testing that also lets you view detailed information about HTTP responses.

  • Steps:
    1. Open Postman.
    2. Enter the URL you want to check and set the method to GET (or another appropriate method).
    3. Send the request.
    4. Look at the status code displayed in the response section.

These methods provide different levels of detail and can be chosen based on your needs—whether you're doing a quick check or need a detailed analysis of HTTP traffic.

Which HTTP Method is used with HTTP 203 Status Code?

The HTTP 203 status code, "Non-Authoritative Information," can technically be used with any HTTP method, as it is not specifically tied to the type of request being made. However, in practice, it is most commonly associated with GET requests. This is because the 203 status code is used to indicate that the entity returned as a response (for example, a web page or an API result) is not a definitive copy from the original source but has been obtained from a local or third-party copy that may have been modified.

Here’s a brief overview of how it could relate to different HTTP methods:

  1. GET: This is the most likely scenario where a 203 might be used. When a client performs a GET request to retrieve data, the server might respond with 203 if the data comes from a cache or a third-party service and may have been altered from the original.

  2. POST: Although less common, it's possible to use a 203 in response to a POST request if the response is derived from processed input data that may include modifications from secondary sources.

  3. PUT and DELETE: These methods are less likely to use a 203 status since they are generally intended to create or alter resources directly on the server or confirm the deletion of resources, respectively. A non-authoritative status would be less meaningful in these contexts.

  4. HEAD: Similar to GET, but since HEAD requests don’t return a body, the use of 203 would only affect the headers, which could still inform the client that the header information might not be authoritative.

In any implementation, it is crucial that the use of HTTP 203 is clearly documented and understood by clients consuming the API or service, as it communicates an important caveat about the nature of the data being provided.

What is the Browser Compatibility of HTTP 203 Status Code?

The HTTP 203 status code, "Non-Authoritative Information," is part of the HTTP/1.1 standard, which is widely supported by all major browsers. However, the direct handling of the 203 status code is more a matter of server and application concern than of browser compatibility.

Here’s what you need to know about browser compatibility and handling of HTTP 203:

  1. General Support: All modern web browsers (like Google Chrome, Mozilla Firefox, Microsoft Edge, Safari, and others) inherently support HTTP/1.1, which includes the ability to receive and process the 203 status code. The browsers will recognize it as a successful response but with the specified caveat of being non-authoritative.

  2. Visibility to Users: Typically, browsers do not explicitly display HTTP status codes to users. So, while a browser knows it has received a 203 response, this is generally not visible to the user directly. Instead, what matters is how the web application handles the response and what content is displayed to the user.

  3. Developer Tools: Developers can see HTTP status codes, including 203, in the network panel of the browser's developer tools. This is useful for debugging and ensuring that APIs and servers behave as expected.

  4. Impact on JavaScript and Web Applications: JavaScript running in the browser can detect HTTP status codes through various APIs, such as the Fetch API or XMLHttpRequest. This allows web applications to programmatically handle specific behaviors based on the received status code.

  5. No Special Handling Required: Unlike some other HTTP status codes that might require specific handling by the browser (like redirects or authentication requests), HTTP 203 does not necessitate any special functionality from the browser. It is treated like other 2xx success status codes in that the request is considered successfully completed.

Best Practices for Handling HTTP 203

Handling the HTTP 203 status code, "Non-Authoritative Information," effectively involves understanding its implications and ensuring that your application processes it appropriately. Here are some best practices for handling this status code:

1. Understand When to Use HTTP 203

Use the HTTP 203 status code to indicate that the response payload, while successful, might not be the exact representation of what would have been obtained directly from the source. It's suitable when the server is returning a response that has been modified by an intermediary, such as:

  • Responses served from a caching system that might have altered the data.
  • Content aggregated from multiple sources or through transformations that change the original data.

2. Clear Documentation

Document the use of HTTP 203 in your API or server responses clearly. Clients or consumers of your API should understand:

  • When and why they might receive a 203 status.
  • How they should interpret the data received with this status.
  • Any actions they might need to take upon receiving such a response.

3. Client-Side Handling

Ensure that client-side applications are programmed to handle a 203 status appropriately. This could involve:

  • Checking the status code of the response and handling it distinctively if necessary.
  • Logging or alerting when a 203 status is received, especially if this is critical for the application's data integrity.

4. Use With Appropriate Content

When sending a 203 status code, consider also providing metadata about the source or nature of the modifications made to the original content. This could include:

  • Headers or JSON fields specifying the last known source of the data.
  • A timestamp of when the data was last modified by the intermediary.

5. Security and Compliance

If your application deals with sensitive or regulated data, ensure that using a 203 status code and modifying data through intermediaries complies with relevant laws and regulations. You might need to:

  • Implement additional security measures to protect data integrity.
  • Provide users with options to request direct data if needed for compliance reasons.

6. Fallback Mechanisms

Consider implementing a mechanism where clients can request the original data directly if they receive a 203 status and deem it necessary to verify the authenticity of the information. This could be facilitated by:

  • An additional API endpoint to access unmodified data.
  • Special request parameters that bypass caches or other intermediaries.

7. Monitoring and Analytics

Monitor the usage and impact of HTTP 203 responses in your system. Analyzing how frequently and under what circumstances they are used can help you:

  • Optimize the performance and reliability of data delivery.
  • Adjust your system's configuration to reduce the necessity of serving modified data when not essential.

8. Educate Your Users

For consumer-facing applications, consider educating your users about what it means when they are interacting with non-authoritative data, especially in contexts where data accuracy and timeliness are critical.


The HTTP 203 status code serves as a valuable tool for web developers and API providers, signaling that the information provided might not directly originate from the primary source and may have been altered. While it's not one of the most commonly used HTTP status codes, its correct application can enhance transparency and trust between servers and clients, particularly in environments where content is aggregated or cached.

Understanding when and how to use the HTTP 203 status code is crucial for maintaining the integrity and credibility of the data served. As we've explored, whether you're dealing with SEO implications, setting up server responses, or ensuring compliance with data regulations, handling this status code properly is key. It allows for a clearer communication path and better decision-making processes for clients consuming the API or visiting the website.

For developers and system administrators, the key takeaway is to implement and document the use of HTTP 203 thoughtfully. This ensures that all parties understand the nature of the data they're receiving and can take appropriate actions based on their specific needs and contexts. As with any tool in web development, the goal is to use it effectively to enhance user experience and support the operational goals of your digital platforms.

By adhering to best practices for using and handling HTTP 203, organizations can ensure that they not only comply with technical standards but also uphold a commitment to delivering reliable and trustworthy digital experiences.

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 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.