When browsing the web or working on a new project, you may encounter different HTTP status codes. Among the less common is the HTTP 303 error, also known as “See Other.” Understanding what it means and how to handle it properly can be crucial. This is especially true for developers working with APIs, form submissions, or redirects.
In this article, we’ll break down what the 303 error means. We’ll cover when it appears, and how you can fix or use it effectively.
What Is a 303 Error?
An HTTP 303 status code isn’t actually an error in the traditional sense—it’s a redirection message.
There are 5 classes or categories of status codes from 1xx – 5xx:
• 1xx informational response – the request was received, alert client to wait for final response.
• 2xx successful – the request was successfully received, understood, and accepted.
• 3xx redirection – further action needs to be taken in order to complete the request.
• 4xx client error – the request contains bad syntax or cannot be fulfilled.
• 5xx server error – the server failed to fulfil an apparently valid request.
This status code belongs to the 3xx redirection status codes along with the status codes from 300-308. Specifically, the 303 status code – See Other indicates that the server is redirecting the client to a different URL.
This is typically used after an HTTP POST request when the server wants to redirect the client to a GET method to retrieve the result.
It instructs the client to perform a GET request at a different URI. It is commonly used in web forms and RESTful APIs.
You can check the differences between the 303, 302, and 307 status codes
| Status Code | Redirect Method | Method Preservation | Common Use |
| 302 | Temporary | May change method | Basic redirects |
| 303 | See Other | Always Get | Post-redirect-get |
| 307 | Temporary | Preserves method | Form resubmission prevention |
When Is the 303 Status Code Used?
The 303 status code is primarily used in situations like:
• RESTful APIs: Used to guide clients from a POST/PUT request to a resource location using a GET request.
• Form submissions: After a user submits a form via POST, the server responds with a 303 to redirect the user to a confirmation or result page.
• Preventing resubmissions: Helps avoid the “resend form” warning when refreshing a page after a POST request.
POST /submit-form HTTP/1.1
Host: example.com
--- response ---
HTTP/1.1 303 See Other
Location: /thank-youThe browser will then automatically perform a GET request to /thank-you.
How to Fix or Handle a 303 Error
- If You’re a Developer
• Use 303 instead of 302 when redirecting after a POST request to enforce a GET on the next request.
• Ensure your web server or backend framework is configured properly to send 303 in scenarios - If You’re a User or Tester
• 303 messages usually happen in the background and are handled automatically by browsers.
• If you’re seeing unexpected redirects or issues, check the browser’s network tab to trace the redirect path.
• Use tools like Postman or cURL to inspect how the server handles requests and which status codes are returned. - If You Encounter Unexpected 303 Behavior
To investigate further, you can check the webserver’s configuration files. Whether you have nginx, Apache or some other webserver running on your server, you can look for redirection rules which are defined differently in each of the webservers.
In nginx “Server blocks” the redirect rule should look something like this:
location /some/path {
return 303 /new/path;
}If you have Apache, you will need to check the Virtualhosts as well as the .htaccess file for additional redirects. The redirects in Apache are usually defined in the following format:
Redirect 303 / http://example.com/payment/
or
RewriteEngine On
RewriteRule ^oldpath/?$ /newpath/ [R=303,L]The same rules apply for Litespeed as it also uses .htaccess file. The rules can be additionaly added from the LiteSpeed Dashboard.
Except for the web servers you can check the HTTP method changes. A 303 should always lead to a GET request, no matter the original method (POST/PUT). It should ensure there are no redirect loops or incorrect URI paths.
If the cause for the 303 error is still not discovered, investigate the application and server logs. Alternatively, use debugging tools to trace where and why the 303 is triggered.
Please note, that some WordPress and other CMS systems have plugins that may automatically add redirects for the intended purpose.
Conclusion
The 303 error is a helpful tool for redirecting users after a form submission or an API action. While it’s often used intentionally, sometimes it can indicate an error or misconfiguration. Understanding its purpose ensures better user experience, API design, and debugging efficiency.
Whether you’re building a REST API, a web form, or troubleshooting HTTP flows, knowing when and how to use the 303 redirect can make your development smoother and more standards-compliant.