redirect from index.php to domain.com/

What you are wanting to do does not make sense to me. It is over optimization, and my instinct suggest it is even a bad practice. If people are linking to index.php figure out why.

This makes total sense… it’s technically the same page but you can reach it from two unique URLs. That’s not so good for search engine rankings as it looks like duplicate content. If you do a 301 redirect from one to the other then you can consolidate your ranking and authority for that page.

This worked for me:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{THE_REQUEST} ^[^/]*/index\.php [NC]
RewriteRule . / [R=301,L]
</IfModule>

But this before the WordPress rules in .htaccess