What is a Redirect Loop? Causes & Fixes

Definition

A redirect loop happens when URL A redirects to B, and B eventually redirects back to A — directly or through a longer chain. Because the destination never resolves, browsers detect the loop and abort with an error like "This page isn't redirecting properly" (Firefox) or "ERR_TOO_MANY_REDIRECTS" (Chrome).

Common causes

• HTTP ↔ HTTPS misconfiguration — HTTPS redirects to HTTP because of a misconfigured load balancer or proxy.
• www ↔ non-www loops — both versions try to be canonical at the same time.
• Trailing slash inconsistencies — /page redirects to /page/ while /page/ redirects back to /page.
• Auth or session redirects — login pages redirect to a destination that bounces back to login because the cookie didn't persist.
• CMS or plugin conflicts writing competing redirect rules.

How to find and fix

1. Use a redirect checker to follow the entire chain and visualize the loop.
2. Inspect server-level redirect rules (.htaccess, nginx, CDN edge rules) for conflicting directives.
3. Audit application-level redirects (middleware, framework router) separately from infrastructure rules.
4. Scan your site to detect URLs that fail to resolve, then trace each one back to its loop.

Redirect loops break the page entirely — every visitor and every crawler gets the error. They are easy to fix once spotted, so monitor for them after every redirect rule change.