Redirects.

Each redirect adds 100-500ms of latency — minimize redirect chains

What does this check test?

This check identifies HTTP redirects (301, 302, 307, 308) that occur before the final page loads. Each redirect requires a full round-trip to the server — DNS lookup, TCP connection, TLS handshake, and HTTP request/response — before the browser can follow the new URL. Redirect chains (A -> B -> C -> D) multiply this penalty. Common redirect patterns include HTTP-to-HTTPS redirects, www-to-non-www (or vice versa), trailing-slash normalization, vanity URLs, locale redirects, and marketing campaign tracking redirects.

Why does it matter?

Each redirect adds 100-500ms of latency on a typical connection, and significantly more on slow mobile networks. A chain of 3 redirects can easily add 1-2 seconds to the page load time before any content even begins to download. Redirects delay every other performance metric proportionally — TTFB, FCP, LCP, and TTI all shift later. On HTTP/1.1 connections, redirects cannot be multiplexed and each one blocks completely. Google specifically penalizes multiple redirects in Lighthouse scoring.

Who is affected?

Sites that have undergone URL restructuring, domain migrations, or use marketing redirect services are most affected. E-commerce sites with complex URL schemes (category/subcategory/product paths that change seasonally), sites that redirect between mobile and desktop versions, and sites with both www and non-www versions configured are common offenders. Analytics-heavy marketing sites that route through multiple tracking domains are especially impacted.

Where does this apply?

Redirects are visible in the Chrome DevTools Network panel — look for 301/302 status codes on the initial navigation. Common redirect sources: HTTP-to-HTTPS upgrade (`http://example.com` -> `https://example.com`), www normalization (`www.example.com` -> `example.com`), trailing slash enforcement, old URL patterns, and third-party analytics redirects. Server configuration files (`.htaccess`, `nginx.conf`, CDN rules) are where most redirects are defined.

How to fix it

server {
  listen 80;
  listen 443 ssl;
  server_name www.example.com;
  return 301 https://example.com$request_uri;
}

add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload";

References

• Avoid multiple page redirects — Chrome Developers
• Redirections in HTTP — MDN
• HTTP Strict Transport Security (HSTS) — MDN