Hi all,
Next Monday, March 30th, we’re going to make a change to improve SEO in sites that have configured a custom domain. I want to tell you a little bit more about it before we roll it out.
Every time you create a new Netlify site, we assign a subdomain for it in our primary domain, netlify.com , for example happy-wozniak-23hdl3.netlify.com . As you might already be aware, on April 14 2020, we’re changing that domain to netlify.app , so that previous example will become happy-wozniak-23hdl3.netlify.app .
When you configure a custom domain for a site, the original subdomain on Netlify’s domain still works — we keep it available for troubleshooting purposes. However, this is not very SEO friendly, and many of you have expressed concerns about Google and other search engines penalizing you because of that. There are several ways to address this problem, and I want tell you about a couple of them before I tell you about how we’re helping you starting next Monday.
The first solution is to use our redirects to send traffic from your Netlify subdomain to your main custom domain. This is a good solution, but it’s a little bit fragile because you need to add more configuration to your site. If you decide to change your memorable subdomain to something even more memorable, like happy-hamilton , you’d have to remember to change the redirects file too.
The second solution is to add canonical links to your html pages. Adding canonical links is the standard way to inform web crawlers to index content only from a specific domain. We recommend people to use this solution because it’s standard, regardless of whether you use Netlify, or any other service. It’s also integrated in many static site generators, so maintenance is easier for you if you use any of those tools. Besides being accepted as html elements, canonical links can also be presented as HTTP response headers.
Since we know that many people don’t add canonical links to their html pages, we’re going to help you with it. Next Monday, we’re going to release a change that will add a new Link HTTP response header to prevent crawlers from indexing content in your Netlify subdomain if you’ve set a custom domain for your site. We will only do this when we receive requests to those Netlify subdomains and your html pages don’t include a a canonical link already. That header will look something like this if you use cURL to send a request to your Netlify subdomain:
> Link: <https://your-custom-domain.com>; rel="canonical"
If your site is proxying requests through another Netlify site, we’ll use the domain that will show in visitors’ address bar in that response headers. If you’re proxying through a different CDN, like Cloudflare, Fastly, or Cloudfront, we recommend you to add canonical link tags to your html, since we cannot detect when traffic is coming through those other providers.
If your site has several alternate domains, besides a specific custom domain, we’ll use the primary custom domain as the canonical domain.
If you want to modify or disable that behavior in any way, we recommend you to set canonical links in your html pages, which is a standard SEO practice. You can also override that header by using Netlify’s headers configuration.
Don’t hesitate to leave a comment in this thread if you have any questions about this change. We’re here to help.
