ERR_TOO_MANY_REDIRECTS on Cloudflare
Why it happens on Cloudflare
SSL mode set to Flexible makes Cloudflare fetch the origin over plain HTTP; the origin then redirects to HTTPS, Cloudflare follows it back to itself, and the loop never ends.
The fix on Cloudflare
SSL/TLS → Overview → set the mode to Full or Full (Strict) and install a certificate on the origin. Flexible mode plus an origin HTTPS redirect is the single most common cause of this error on the web.
Is ERR_TOO_MANY_REDIRECTS happening on your domain?
The uptime probe returns the full redirect chain, so you can see the exact two URLs bouncing off each other instead of inferring it from behaviour.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
If that didn't fix it
Cloudflare has its own failure mode, but ERR_TOO_MANY_REDIRECTS has a wider set of causes that apply everywhere. The most common one overall is: the cdn forwards to the origin over http while the origin redirects all http to https — an infinite loop.
All causes and fixes for ERR_TOO_MANY_REDIRECTS