HTTP 303 Status Code: What It Means for Your SEO

HTTP redirects are one of the quietest ways to lose SEO rankings. Set up the wrong one, and Google stops passing authority from your old URL to the new one. Set up none at all, and rankings built over months can disappear overnight. The 303 status code causes regular confusion because it looks like a redirect but behaves very differently from the codes that actually protect your SEO.

Understanding which redirect code to use is a technical SEO fundamental that affects how much authority your pages carry and how reliably Google can crawl your site. This article explains the difference between 301, 302, and 303, and when each one applies.

Table of Contents

• How HTTP redirect codes work
• 301 vs 302: the two redirects that protect your rankings
• What HTTP 303 actually does, and why it is not for SEO
• When 303 does have a valid use
• How rankingCoach helps you catch technical SEO issues
• Frequently Asked Questions

How HTTP redirect codes work

When a URL changes, HTTP redirect codes are the signals that tell browsers and search engines where to go instead. They belong to the 3XX family of HTTP status codes, where each code communicates a different type of redirect behaviour. For SEO, the critical question is whether the redirect transfers page authority to the new URL and whether it signals a permanent or temporary change.

Getting this wrong has real consequences. A redirect that does not pass authority means all the backlinks and ranking signals the original page accumulated stay attached to a URL that no longer exists. The new page starts from zero, even if it contains identical content.

301 vs 302: the two redirects that protect your rankings

For most URL changes on a website, you need one of two codes:

• 301 (Permanent redirect): Signals a permanent move. Google transfers almost all of the link equity from the old URL to the new one, preserving the rankings and authority the original page built. Use this for site migrations, domain changes, switching from HTTP to HTTPS, and any URL restructuring you do not plan to reverse. If you are ever unsure, 301 is almost always the right answer for a lasting change.
• 302 (Temporary redirect): Signals a temporary move. Google keeps the original URL indexed and does not transfer link equity, because it expects the original page to return. Use this for A/B tests, maintenance pages, or short-term promotional redirects. Using a 302 for a permanent change is a common mistake that causes the original page to lose rankings without the new one ever gaining them.

What HTTP 303 actually does, and why it is not for SEO

The 303 code is also a redirect, but it sends a different message. When a server returns a 303, it tells the browser: "The resource you requested is not here, but here is something related." It does not say this page has moved permanently, and it does not say come back later. It says try this instead.

That distinction matters for SEO. A 303 does not pass link equity to the destination URL the way a 301 does. Google does not interpret it as a permanent move, so any authority the original page built does not transfer. Using a 303 where a 301 or 302 belongs is similar to asking Google to follow a new signpost while leaving the old one pointing in the wrong direction.

If you have come across a 303 in your site audit and were planning to use it for a URL change, stop. Switch to:

• 301 if the change is permanent
• 302 if it is temporary

When 303 does have a valid use

The 303 code exists for a specific and legitimate purpose: preventing form resubmission. When a visitor submits a form and then presses the back button or refreshes the page, the browser would normally resend the form data. A 303 redirect after form submission sends the user to a confirmation page instead, preventing duplicate submissions without triggering a second POST request to the server.

This is a server-side concern, not an SEO concern. The key takeaways are:

• 303 has a valid role in web development for handling form submissions
• It is not designed for managing URL changes or preserving search rankings
• If you are not building web application forms, you are unlikely to ever need to configure one

How rankingCoach Helps You Catch Technical SEO Issues

rankingCoach's full site scan analyses your website and surfaces SEO issues with clear fixes provided for each one. Alongside clear SEO tasks and progress tracking, it guides you through what needs to be resolved and in what order, so technical problems do not go unnoticed.

The AI Content Optimizer helps you optimize the pages your redirects point to, so the authority that transfers goes somewhere that is properly set up to rank.

The AI Visibility feature shows how your business appears in AI-generated answers from tools like ChatGPT, Perplexity, and Gemini, giving you a complete picture of your search presence beyond traditional rankings.

Frequently Asked Questions