Uppercase vs Lowercase in URLs: Does Case Affect SEO?

Short answer: always use lowercase URLs. Here's why it matters.

Are URLs Case-Sensitive?

It depends on the server:

Linux servers (Apache, Nginx): Case-sensitive. /About-Us and /about-us are different pages.
Windows servers (IIS): Case-insensitive. Both resolve to the same page.
Most cloud platforms: Case-sensitive by default.

Duplicate content: If /About and /about both work, Google may index both as separate pages with duplicate content.
Link equity split: Backlinks to different cases split your page authority.
Crawl budget waste: Googlebot may crawl multiple case variants.

Always use lowercase. Set up 301 redirects from uppercase variants to lowercase. In Nginx:

if ($uri ~ [A-Z]) {
  return 301 $scheme://$host$uri_lowercase;
}

Our URL slug generator always outputs lowercase, hyphen-separated slugs.