301 vs 308 Redirects: Why Method Matters for SEO

TL;DR

The critical difference between a 301 and a 308 redirect lies in how they handle HTTP request methods. A 301 'Moved Permanently' redirect allows the request method to change, often from POST to GET, which can break functionality for forms or API calls. In contrast, a 308 'Permanent Redirect' strictly preserves the original request method. For SEO, Google treats both as permanent signals that pass link equity, but using a 308 is the technically safer and more precise choice for pages that handle data submissions.

The Core Difference: How 301 and 308 Handle Request Methods

When you need to permanently move a web page, you use a redirect to tell browsers and search engines about the new location. The two primary options for this are the 301 and 308 status codes. While both signal a permanent move, they differ in one crucial technical detail: the handling of the HTTP request method.

A 301 'Moved Permanently' redirect has been the standard for years. When a browser receives a 301, it understands the page has moved for good. However, the specification allows the browser to change the request method from the original (e.g., POST) to a GET method. A POST request is used to send data to a server, such as when you submit a contact form or log in. A GET request is used to retrieve data. This change can cause problems; if a user submits a form on a URL that gets a 301 redirect, the browser might follow up with a GET request to the new URL, losing the submitted form data in the process.

A 308 'Permanent Redirect' solves this problem. It was introduced to be a stricter version of the 301. A 308 redirect explicitly forbids changing the request method. If the original request was a POST, the browser is required to make a POST request to the new URL, preserving all the original data. This makes it essential for maintaining the functionality of web applications, APIs, and any page that handles user submissions during a permanent move. As noted by Semrush, this preservation is critical for ensuring a seamless user experience in e-commerce checkouts or login processes.

This distinction is the fundamental factor in choosing between them. To put it simply, the 301 is flexible with the method, while the 308 is rigid. Here is a clear breakdown:

SEO Implications: Does Google Prefer 301 or 308?

For search engine optimization professionals, the primary question is which redirect is better for rankings. The answer from Google is clear: for ranking purposes, there is no difference. Both 301 and 308 redirects are treated as strong signals that a page has moved permanently, and both will pass PageRank and other ranking signals to the new URL. This has been confirmed multiple times by Google representatives like John Mueller.

According to an article from Infidigit, John Mueller stated that Google's crawlers treat 308s the same as 301s. He described 308s as 'technically cleaner' in situations where you are unsure what kind of request a site receives, but for most websites where requests are primarily GET, the outcome is identical. The consensus is that you should use the redirect that is technically correct for the situation without worrying about one having an SEO advantage over the other.

However, there are indirect SEO implications to consider. Using the wrong redirect can negatively impact user experience, which is a significant ranking factor. For example, if you use a 301 redirect on a form submission page and it causes the user's data to be lost, they will likely become frustrated and leave. This can lead to increased bounce rates and lower engagement signals, which can harm your SEO performance over time. Therefore, while Google's crawler may not differentiate, choosing the correct redirect is vital for maintaining a positive user experience and, by extension, strong SEO health.

While the 301 is more established and universally supported by older systems, the 308 is now a well-defined standard and the proper choice for modern web applications. The key takeaway for SEO is to prioritize technical correctness to ensure site functionality and user satisfaction.

Practical Use Cases: When to Use 301 vs. 308

The choice between a 301 and 308 redirect depends entirely on whether you need to preserve the original HTTP request method. Making the right choice ensures your website functions as intended for users and search engines.

When to Use a 301 Redirect (Method Change is Acceptable)

A 301 redirect is the go-to choice for most standard redirection tasks where only GET requests are involved. It is perfectly safe and effective in these scenarios:

• Migrating an entire website to a new domain: When moving from `oldsite.com` to `newsite.com`, a 301 is the standard for redirecting all pages.
• Changing URL structures for static content: If you're updating your blog's URL pattern from `/blog/post-name` to `/articles/post-name`, a 301 will correctly pass link equity. Managing large volumes of content during such migrations can be complex. For marketers and creators looking to streamline their workflow, platforms like BlogSpark offer AI-powered tools that can help generate and manage SEO-optimized articles, making the technical task of redirection part of a more efficient content lifecycle.
• Redirecting HTTP to HTTPS: For standard informational pages, a 301 is sufficient to move users and bots to the secure version of your site.
• Consolidating duplicate content: When you have multiple URLs with similar content, a 301 redirect can point them all to a single canonical version.

When to Use a 308 Redirect (Method Preservation is Critical)

A 308 redirect is essential in any situation where a request method other than GET must be maintained. It prevents functionality from breaking in interactive parts of your website.

• Redirecting form submission pages: This is the most critical use case. Contact forms, login pages, and e-commerce checkout processes that use POST requests must use a 308 to avoid losing user-submitted data.
• Moving API endpoints: Web applications that rely on API endpoints using methods like POST, PUT, or DELETE must use 308 redirects to ensure the client's request is not altered.
• Redirecting any resource where client-side actions depend on the original method: If your site has complex JavaScript that expects a certain request method, a 308 ensures that logic does not fail after a redirect.

Broader Context: How 301/308 Compare to 302/307 Temporary Redirects

Understanding permanent redirects is only half the picture. It's equally important to distinguish them from their temporary counterparts: 302 and 307 redirects. Using the wrong type—permanent versus temporary—can send confusing signals to search engines and harm your SEO.

The core difference is intent. 301 and 308 redirects signal a permanent move, telling search engines to update their index and transfer link equity. 302 and 307 redirects signal a temporary move, instructing search engines to keep the original URL indexed because you intend to bring it back. As explained by StoryChief, this distinction is crucial for SEO health.

Just as 308 is the method-preserving version of 301, the 307 'Temporary Redirect' is the method-preserving version of the 302 'Found' redirect. A 302 allows the request method to change (like a 301), while a 307 requires the method to be preserved (like a 308). This parallel structure makes it easy to choose the right temporary redirect based on your technical needs.

Here is a complete comparison of all four common redirect types:

Choosing the correct redirect is a fundamental aspect of technical SEO. Use permanent redirects (301, 308) for changes that will last forever and temporary redirects (302, 307) for short-term moves like maintenance or testing. Always select the method-preserving option (307, 308) when dealing with forms or APIs.