how to redirect https://www.example.com to https://example.com with .htaccess?

Question

www.example.com will redirected to https://example.com .

https://www.example.com will not redirected to https://example.com . How to do this?

The current rules looks like this:

RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^[a-z0-9-]+\. [NC]
RewriteCond %{HTTP_HOST} ^(?:[a-z0-9-]+\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [L,NE,R=301]

RewriteCond %{HTTPS} on [OR]
RewriteCond %{HTTP_HOST} ^[a-z0-9-]+\.[NC]
RewriteCond %{HTTP_HOST} ^(?:[a-z0-9-]+\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L,NE]

Answer 1

 RewriteCond %{HTTP_HOST} ^[a-z0-9-]+\.[NC]

You are missing a space before the flags argument, so it becomes part of the CondPattern and it never matches, so the second redirect block (from HTTPS) never happens.

However, this should still be caught by the first rule block, but... this looks like it would create a small redirect loop since the regex ^[a-z0-9-]+\. matches www. , but it would also match example. (after the first redirect). Potentially redirecting to https://com/foo ??

You don't need both rules.

Try the following instead:

RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [L,NE,R=301]

You will likely need to clear your browser cache before testing. (Test with 302 to avoid caching issues.)

But what´s the advantage to do so?

In hardcoding the canonical hostname... it depends on whether you have other subdomains or domains pointing to the same account.

A hardcoded solution is simpler, less prone to error and generally more reliable.