“cross Origin Requests Are Only Supported For HTTP.” Error When Loading A Local File

The error message "Cross origin requests are only supported for HTTP" typically occurs when you are trying to make an XMLHttpRequest from a local file (e.g., file:///path/to/file.html) to another local file or a different domain.

By default, web browsers enforce the Same Origin Policy, which restricts making requests from one origin (domain, protocol, and port) to another. This policy is in place to prevent potential security vulnerabilities.

In your case, loading a local file (file://) does not fall under the HTTP protocol and is considered a different origin from other HTTP-based resources. Hence, making cross-origin requests from a local file to an HTTP resource is not supported, causing the mentioned error.

To overcome this limitation, you can set up a simple HTTP server locally to serve your files, allowing you to make requests between them. Here are two common methods to set up an HTTP server:

  1. Using a programming language:

    • If you have Node.js installed, you can use packages like http-server, express, or live-server, which provide simple HTTP servers for static file hosting.
    • Alternatively, you can use Python’s built-in http.server module by running the command python -m http.server or python -m SimpleHTTPServer.
  2. Using browser extensions:

    • Various browser extensions, such as "Web Server for Chrome" (Chrome) or "MAMP" (Firefox), allow you to serve files from a local directory easily.

By serving your files through an HTTP server, you will be able to make cross-origin requests without any issues.

About the Author Rex

I'm a passionate tech blogger with an insatiable love for programming! From my early days tinkering with code, I've delved into web dev, mobile apps, and AI. Sharing insights and tutorials with the world is my joy, connecting me to a global community of like-minded tech enthusiasts. Python holds a special place in my heart, but I embrace all challenges. Constantly learning, I attend tech conferences, contribute to open-source projects, and engage in code review sessions. My ultimate goal is to inspire the next generation of developers and contribute positively to the ever-evolving tech landscape. Let's code together!