What Is 301 error

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Last updated: April 15, 2026

Quick Answer: A 301 error, more accurately a 301 HTTP status code, indicates a permanent redirect from one URL to another. It tells browsers and search engines that the requested page has moved permanently, with a redirect rate of 98% success when properly implemented.

Key Facts

The 301 status code was introduced in HTTP/1.0 in 1996
301 redirects preserve about 90–95% of SEO ranking power
Google recommends 301s for site migrations and domain changes
Improper 301s can cause redirect loops, increasing bounce rates by up to 40%
A 301 response includes a 'Location' header specifying the new URL

Overview

A 301 error is not actually an error in the traditional sense but an HTTP status code indicating that a requested web page has been permanently moved to a new location. This status code is part of the Hypertext Transfer Protocol (HTTP) standard, used by servers to communicate with browsers and search engines about the status of a web request.

When a user or crawler attempts to access a URL that returns a 301 status, the server automatically redirects them to the new URL. This ensures continuity of access and helps maintain SEO value, as search engines transfer most of the original page's authority to the new address.

Permanent Redirect: A 301 status explicitly signals that the move is permanent, not temporary, influencing how search engines index the content.
SEO Preservation: Search engines pass approximately 90–95% of the original page's link equity to the new URL after a 301 redirect.
Implementation: Webmasters implement 301s via server configuration files like .htaccess (Apache) or using server-side scripts such as PHP or Node.js.
Browser Handling: Modern browsers process 301 redirects instantly, typically without user intervention, improving the user experience during site migrations.
Cache Behavior: Browsers and proxies may cache 301 redirects indefinitely, which can cause issues if the redirect is later removed or changed.

How It Works

Understanding the technical mechanism behind a 301 redirect clarifies why it's essential for website management and SEO. When a client requests a URL, the server responds with a 301 status and includes a Location header pointing to the new URL.

HTTP Request: The client sends a GET request to the original URL, initiating the communication process with the web server.
Server Response: The server replies with a 301 Moved Permanently status code and includes the new URL in the Location header field.
Redirect Execution: The browser automatically follows the new URL specified in the header, typically without user input or delay.
Search Engine Indexing: Googlebot and other crawlers interpret the 301 as a signal to update their index, replacing the old URL with the new one.
Link Equity Transfer: Backlinks pointing to the old URL transfer most of their SEO value—estimated at 90–95%—to the destination page.
Canonicalization: 301 redirects help consolidate duplicate content by directing multiple URLs to a single canonical version.

Comparison at a Glance

Below is a comparison of HTTP redirect types, highlighting key differences in use cases and SEO impact:

Code	Name	Meaning	SEO Impact	Use Case
301	Moved Permanently	Page has permanently moved	High (90–95% equity transfer)	Site migrations, domain changes
302	Found (Temporary)	Page is temporarily elsewhere	Low (no equity transfer)	A/B testing, maintenance
307	Temporary Redirect	Preserves original method	None	Secure temporary moves
308	Permanent Redirect	Like 301 but method-safe	High	APIs, modern applications
404	Not Found	Page does not exist	Lost traffic and rankings	Broken links, deleted pages

While 301 redirects are ideal for permanent moves, temporary options like 302 and 307 are better for short-term changes. Misusing a 301 when a 302 is needed can lead to indexing errors and lost SEO value. The 308 status, introduced in 2015 with HTTP/1.1, is a stricter version of 301, ensuring HTTP methods like POST are preserved.

Why It Matters

For website owners, developers, and SEO professionals, understanding and correctly implementing 301 redirects is critical to maintaining traffic, rankings, and user experience during site changes. These redirects ensure that visitors and search engines are seamlessly directed to the correct pages.

Site Migrations: When moving a site to a new domain, 301s preserve traffic and prevent ranking drops by transferring SEO equity.
HTTPS Transitions: Switching from HTTP to HTTPS requires 301 redirects to ensure secure access and maintain search visibility.
URL Standardization: Redirecting non-www to www (or vice versa) consolidates authority and avoids duplicate content penalties.
Broken Link Recovery: Fixing 404 errors with 301s to relevant pages reduces bounce rates and improves user engagement.
E-commerce Updates: When product pages are restructured or retired, 301s guide customers to new or similar items.
Content Mergers: Combining multiple outdated pages into one updated resource requires 301s to maintain inbound link value.

Improper use of 301 redirects—such as creating chains or loops—can degrade site performance and confuse search engines. Best practices recommend using direct, single-hop redirects and updating internal links to point to the final destination URL.