Read magento 2 too many redirects for more information.
If you are experiencing error like, TOO MANY REDIRECTS on your Magento store, then the issue is because of your .htaccess file or your cache folder.
Place a new copy of .htaccess from a fresh magento package and delete the cache and session folder as well. Then refresh and it should be good.
Or another way is,
In the “core_config_data” table remove the value of “web/cookie/cookie_domain” and set “web/cookie/cookie_httponly” to “0”. Clear the cache by removing the files in “var/cache”.