.htaccess redirect – differences between two redirects

Question

Could you explain the difference between the two .htaccess redirects below?

The first redirect is the one I tend to use the most but it didn't work on a recent site (too many redirects – even though I didn't have any set up) but the second redirect worked and I'm curious.

RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

RewriteEngine On
RewriteCond %{ENV:HTTPS} !=on
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]

Answer 1

The first RewriteCond checks the HTTPS flag set by the server (Check this link. Scroll to Server Variables).

The second RewriteCond checks an environment variable, which could be set by a prior RewriteRule (See Setenvvars for setting an environment variable).

Did you try using %{HTTPS} !=on?

RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Note: Both links refer to the apache documentation. Depending on your used HTTP Server this might not work.