What Is 3xx Status Codes In SEO

3xx status codes are the HTTP response class that signals redirection: the requested URL is not the final destination and another URL should be requested instead. In SEO, these codes govern how search engines and users move between URLs during site migrations, content consolidation, and canonicalization.

The codes most relevant to SEO work are 301, 302, 303, 307, and 308, each with different permanence and request-method behavior. Misusing them creates ambiguity about which URL should be indexed and which signals should be consolidated. Getting the code right is the difference between a clean migration and months of lost organic traffic.

Below is the practical taxonomy: how every 3xx code actually works, the difference between 301 and 302, the less common 303/307/308 variants, how redirects behave in crawling and indexing, and the redirect problems that quietly hurt rankings on established sites.

The 3xx Family: How Redirect Codes Actually Work

Every 3xx response includes a Location header that points to the next URL the client should request. A browser or crawler receives that header, follows the new URL, and either lands on a final page or hits another redirect.

Picture URL A redirecting to URL B, which then serves a 200 OK with the actual content. From the user’s perspective, they never see URL A. From the search engine’s perspective, only the final URL is the candidate for indexing, not the redirecting one in the middle.

This mechanism turns one URL into a pointer for another. Multiple pointers can be chained: URL A to URL B to URL C, and so on. MDN’s HTTP status code reference documents the full set of 3xx codes and their exact semantics.

Google’s crawlers follow up to 10 redirect hops by default. Past that limit, the crawler may stop and treat the URL as broken. The core purpose of the 3xx class is to preserve accessibility and signal integrity when URLs change, rather than returning a dead-end error.

301 vs 302: The Two Codes Every SEO Must Know

Two redirect codes account for the vast majority of SEO redirect work: 301 and 302. They look almost identical at a glance, but they communicate different intent to search engines, and that difference has practical consequences.

A 301 redirect says the URL has permanently moved; the old URL should be replaced by the destination in the index. A 302 redirect says the move is temporary; the original URL should remain the canonical one, and the destination is just where visitors are being routed for now. The 301 is the most commonly recommended code in SEO for migrations, slug changes, and content consolidation.

Permanence vs. Temporariness

301 says the URL is gone, use the new one permanently. 302 says the URL is still here, just go here for now. That is the entire conceptual divide between them.

What That Means for Search Engines

Search engines use the permanence signal to decide which URL to index and which signals to consolidate. Using 302 for a permanent move can leave the wrong URL indexed and split link signals between the two versions.

303, 307, and 308: The Method-Preserving Redirects

Three additional 3xx codes handle the same redirection job but with stricter rules about the HTTP request method:

• 307 is a temporary redirect that preserves the original request method. A POST stays a POST, a GET stays a GET.
• 308 is the permanent equivalent of 307, also preserving the request method. Think of it as a method-preserving 301.
• 303 tells the client to convert the request to GET when following the redirect, which is why it is often used after form submissions or other non-GET actions.

From a crawling standpoint, 307 and 308 behave much like 302 and 301 for most SEO use cases. The practical difference matters more for developers who need non-GET requests to survive the redirect correctly, such as form posts, API calls, or anything that relies on the request method being preserved.

How 3xx Redirects Behave in Crawling and Indexing

Crawlers follow redirects, but each hop in a chain costs time and crawl budget. Google’s documented default is to follow up to 10 redirect hops; beyond that, the crawler may stop and treat the URL as broken. Short, direct redirects are materially better than long ones, even when both eventually resolve.

Search engines generally index the final URL after following a redirect, not the redirecting URL itself. This is why a properly implemented 301 from an old page to a new page results in the new page showing up in search results while the old one disappears from the index. Google’s documentation on HTTP status codes covers how Googlebot handles these situations.

Redirects also consolidate link and relevance signals from the old URL to the destination. Backlinks, internal links, and ranking signals associated with the old URL are transferred through the redirect, which is exactly why redirects are central to site migrations and URL cleanup. Lose the redirect, lose the signal.

For sites with complex redirect histories, working with a technical SEO partner like Clickside can surface signal loss that standard crawlers tend to miss.

Common 3xx Problems That Quietly Hurt SEO

Redirects are easy to set up and easy to get wrong. The most common failures are configuration mistakes, and they accumulate quietly. Four issues account for most of the damage in real-world audits:

• Redirect chains: URL A to URL B to URL C wastes crawl budget and adds latency compared with a single direct hop.
• Redirect loops: URLs pointing back to each other cause “too many redirects” errors and prevent indexing.
• Internal links pointing to redirecting URLs create unnecessary extra hops and should be updated to the final destination.
• Soft redirects: redirection-like behavior without the correct HTTP status confuses crawlers and produces inconsistent indexing.

A full audit from Clickside’s technical SEO team typically catches all four of these patterns in a single pass and returns a prioritized fix list.

Getting 3xx Redirects Right

The right 3xx code is the one that matches the move’s permanence and preserves the request method correctly. 301 for permanent moves, 302 for short-term ones, 307 and 308 when the request method must survive the redirect, 303 after a non-GET action that should land on a GET.

Run a site audit to identify redirect chains, loops, and internal links pointing to redirecting URLs. Resolve them in as few hops as possible, point internal links directly at final destinations, and re-crawl after any structural change to confirm the redirect map still resolves cleanly.