How to Fix ERR_TOO_MANY_REDIRECTS — Redirect Loop Fix

ERR_TOO_MANY_REDIRECTS means the browser followed more than 20 redirects and gave up. Each redirect sent it back to a URL it had already visited — a loop. The fix is always removing one direction of the loop.

The most common cause: Cloudflare SSL Flexible mode

Cloudflare SSL "Flexible" means Cloudflare connects to your origin over HTTP, even when users connect over HTTPS. If your origin has an HTTP→HTTPS redirect, this creates a loop:

User → HTTPS → Cloudflare → HTTP → Your origin → 301 HTTPS → Cloudflare → HTTP → ...

Fix: change SSL mode to Full (Strict)

Cloudflare Dashboard → SSL/TLS → Overview
→ Change "Flexible" to "Full (Strict)"

# Full (Strict) requires a valid SSL certificate on your origin
# Let's Encrypt works — install with Certbot:
certbot --nginx -d example.com -d www.example.com

Cloudflare + Vercel loop

Cloudflare Dashboard → SSL/TLS → Overview
→ Set to "Full" (not Flexible, not Full Strict)
# Vercel's certificate is valid — Full mode works correctly

Pure Nginx loop (no CDN)

Two server blocks redirecting to each other, or a return 301 inside the HTTPS block:

# Wrong — causes loop
server { listen 443 ssl; return 301 https://$host$request_uri;  # ← redirects to itself
}

# Correct — only the HTTP block redirects
server { listen 80; server_name example.com www.example.com; return 301 https://example.com$request_uri;
}

server { listen 443 ssl; server_name example.com; # NO return 301 here root /var/www/html;
}

Apache loop — missing X-Forwarded-Proto check

# Wrong — fires on HTTPS requests too
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

# Correct — only fires on actual HTTP
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

Debug with curl (bypasses browser cache)

# Follow the chain and show each hop
curl -sIL --max-redirs 10 https://yoursite.com | grep -E "^HTTP|^[Ll]ocation"

# If you see the same URL appearing twice, that's the loop

Cookie-caused loops

Some redirect loops only happen in the browser, not in curl. This means a cookie is causing the redirect. Test in an incognito window or clear site cookies — if it works, a cookie is the cause.