Cloudflare is a low effort, fast way to serve your site via SSL. Making it work, however, requires keeping a few things in mind, both as it relates to MODX Revolution and to MODX Cloud. Learn more about configuring Cloudflare for MODX and MODX Cloud.
A frequently used practice in MODX is to use a base href tag in templates, for a variety of reasons (learn more). To prevent SSL-related browser warnings, use the following base href tags in your MODX website:
Then you can turn on SSL in Cloudflare using the Flexible HTTPS setting under the Crypto page, and by adding one more page rule to force HTTPS as follows, with the only rule being Always Use HTTPS: