RewriteEngine On
# redirect from http://domain/index.php?url=23e2323 to http://domain/23e2323
# or from http://domain/?url=23e2323 to http://domain/23e2323
RewriteCond %{THE_REQUEST} ^(GET|HEAD) /(index.php)??url=([a-zA-Z0-9]+)([^ ]*)
RewriteRule ^ /%3?%4 [L,R=301]
# rewrite query from http://domain/23e2323 to http://domain/?url=23e2323 without redirect
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z0-9]+)/?$ /?url=$1 [L,QSA]
