HTTP 301 Moved Permanently

What It Means

The HTTP 301 Moved Permanently status code indicates that the requested resource has been permanently moved to a new URL. Clients should update their bookmarks and search engines will transfer SEO value to the new URL.

SEO Impact

PageRank Transfer

301 redirects pass approximately 90-99% of link equity (PageRank) to the new URL. Search engines treat the new URL as the canonical version.

When to Use 301

Domain changes: Moving from old-domain.com to new-domain.com
URL restructuring: Changing /blog/post-123 to /articles/post-title
HTTPS migration: Redirecting HTTP to HTTPS
Merging content: Combining duplicate pages
www normalization: Redirecting www to non-www (or vice versa)

Example Response

HTTP/1.1 301 Moved Permanently
Location: https://example.com/new-page
Content-Type: text/html

<html>
<body>
  This page has moved to
  <a href="https://example.com/new-page">here</a>.
</body>
</html>

301 vs 302 vs 308

Code	Type	SEO
301	Permanent, may change method	Passes link equity
302	Temporary	Keeps original indexed
308	Permanent, preserves method	Passes link equity

Implementation Examples

Nginx

server {
    listen 80;
    server_name old-domain.com;
    return 301 https://new-domain.com$request_uri;
}

Apache (.htaccess)

Redirect 301 /old-page https://example.com/new-page

Next.js

// next.config.js
module.exports = {
  async redirects() {
    return [
      {
        source: '/old-page',
        destination: '/new-page',
        permanent: true, // 301
      },
    ]
  },
}

Common Mistakes

Redirect chains: A → B → C. Keep it to one hop
Redirect loops: A → B → A causes infinite loops
Using 301 for temporary changes: Use 302 instead
Not updating internal links: Fix links, don't rely on redirects