Navigation Failed Because The Request Was For An Http Url With Https-only Enabled < Top 50 EXTENDED >

April 14, 2026 | Reading Time: 4 minutes

The golden rule of 2026 is simple: APIs, images, iframes, and fonts.

// Option C: Just use a relative path if on the same origin fetch('/api/data'); If the browser is trying to access your http:// resource because your server is misconfigured, you can train the browser to never use HTTP again via HTTP Strict Transport Security (HSTS) . April 14, 2026 | Reading Time: 4 minutes

fetch('http://mybackend.com/api/data'); <img src="http://cdn.example.com/logo.png">

This is not a server error (404, 500). It is a client-side refusal . The request never actually left your browser. It is a client-side refusal

https://yourapp.com/api/proxy ➔ Your Server (Node.js/NGINX): http://legacy-vendor.com/data ➔ Back to Browser.

HTTPS-Only mode forces the browser to automatically upgrade every request to HTTPS. If the upgrade fails (or if you explicitly hardcode http:// ), the browser throws an error instead of falling back to unsafe HTTP. You cannot fix this by telling your users to turn off HTTPS-Only mode. Instead, you need to fix your code or infrastructure. Fix 1: Use Protocol-Relative or Absolute HTTPS URLs (The Easiest) Never hardcode http:// or https:// in your frontend code. Use protocol-relative URLs (starting with // ) or absolute paths. HTTPS-Only mode forces the browser to automatically upgrade

// Option A: Protocol-relative (Uses whatever the parent page uses) fetch('//mybackend.com/api/data'); // Option B: Absolute HTTPS (Forces encryption) fetch('https://mybackend.com/api/data');