Fixing the “Failed to execute ‘createObjectURL’ on ‘URL’: Overload resolution failed” Error

What Causes the “Overload Resolution Failed” Error?

The createObjectURL() method accepts a File, Blob, or MediaSource object and returns a unique URL representing that object. For example:

const file = new File(["Hello"], "hello.txt");

const url = window.URL.createObjectURL(file);

This allows you to set image src attributes, download links, and other properties requiring a URL to point to a generated object URL instead of a file on a server.

The overload resolution failed error occurs when the browser cannot determine which version of createObjectURL() to call based on the object you passed in.

The main reasons this can happen are:

• Passing an incompatible object type like a string or array instead of File, Blob, or MediaSource
• Browser compatibility issues where older browsers don’t support certain object types
• Using createObjectURL() in the wrong context, like a web worker
• Conflicts with other code or extensions overriding createObjectURL()

Essentially the browser expects a specific set of object types, and gets confused if you pass something it doesn’t recognize.

Fixes and Solutions

There are a few ways to fix the overload resolution failed error:

1. Make Sure You’re Passing a Valid Object Type

Double check that the object you’re passing to createObjectURL() is a File, Blob, or MediaSource object.

For example, don’t pass a string:

// Causes error 
const invalidUrl = URL.createObjectURL("hello.txt");

Make sure the object is an instance of the correct class:

// Fix by passing a File object
const file = new File(["Hello"], "hello.txt"); 

const validUrl = URL.createObjectURL(file);

If necessary, wrap strings or array buffers in a Blob object:

// Wrap string in Blob
const text = "Hello world";
const blob = new Blob([text]);

URL.createObjectURL(blob);

2. Check Browser Compatibility

Some older browsers don’t support the File or Blob types. Make sure you’re running a modern browser like Chrome, Firefox, Edge, or Safari 10+.

Also double check that Blob and other APIs are supported in your target browsers. You may need polyfills or transpilation for full cross-browser support.

3. Avoid createObjectURL() in Web Workers

The createObjectURL() method is not available in web workers. Instead of URL, web workers have access to Blob URLs created via Blob.prototype.

So instead of:

// Web worker - causes error
const objectUrl = URL.createObjectURL(myBlob);

Use:

// Web worker - correct 
const blobUrl = myBlob.url;

4. Check for Overrides or Extensions

Some browser extensions or libraries override the native createObjectURL() method, which can cause issues.

Try testing in incognito/private browsing mode with extensions disabled as a debugging step.

Also search your codebase for any custom createObjectURL() implementations that could conflict.

5. Upgrade Browser Version

Upgrading to the latest browser version can resolve issues caused by browser bugs or lack of support for newer standards.

For example, Firefox 65 and below do not support passing MediaSource objects to createObjectURL(). Upgrading Firefox will add support.

Best Practices for createObjectURL()

To avoid overload resolution issues in the future, here are some best practices when using createObjectURL():

• Always check browser compatibility and use polyfills as needed
• Validate object types before passing to createObjectURL()
• Avoid using in web workers, use Blob URL directly
• Clean up object URLs by calling URL.revokeObjectURL()
• Use inside try/catch blocks to catch errors
• Use generated URLs immediately, don’t store for later use
• Watch out for overrides from extensions or libraries

Here is an example following these best practices:

// Check for browser support
if (window.URL && window.URL.createObjectURL) {

  try {
    // Validate object type 
    const blob = new Blob(["Hello world"], {type : 'text/plain'});

    if (blob instanceof Blob) {

      // Create and use object URL 
      const url = URL.createObjectURL(blob);

      const link = document.getElementById("myLink");
      link.href = url; 
      link.textContent = "Download file";

      // Revoke object URL 
      URL.revokeObjectURL(url);

    } else {
      throw new Error("Invalid blob object");
    }

  } catch (error) {
    console.error(error.message);
  }

} else {
  console.log("createObjectURL() not supported"); 
}

This wraps createObjectURL() in checks for browser support, validates the object type, uses try/catch for errors, and revokes the URL when done.

Following these practices will help avoid overload issues and make your code more robust.

Other Solutions

If you run into “overload resolution failed” errors even after trying the above fixes, here are a few other things to try:

• Simplify object creation – Instead of passing complex MediaSource or File objects, try passing simpler Blobs.
• Rename variables/parameters – Oddly enough, rename variables may resolve issues if they happen to conflict with internal analytics code.
• Try passing objects directly – Instead of storing in a variable first, pass objects directly:

URL.createObjectURL(new Blob());

• Update analytics or ad blocker extensions – Some extensions are known to cause createObjectURL conflicts.
• Check other extensions and frame contexts – Issues can arise from chrome extensions injecting code into pages.
• Use a different method – Try FileReader, URL.createForBlob(), or other methods to load objects instead.
• Report browser bugs – If all else fails, report confusing overload errors to browser vendors as bugs.

With some tweaking and experimentation, the overload issue should be solvable in most cases.

Conclusion

The “Failed to execute ‘createObjectURL’ on ‘URL’: Overload resolution failed” error occurs when browsers can’t resolve which createObjectURL() version to call based on the passed object.

To fix it, ensure you are passing valid File, Blob or MediaSource objects based on browser support. Avoid using createObjectURL() in web workers, watch out for overrides, and follow best practices for cleaning up URLs.

With proper object validation, browser compatibility checks, and try/catch blocks, you can avoid this error and successfully use createObjectURL() in your projects.

The method allows powerful functionality like generating object URLs that can be used for downloads, dynamic images, media streams, and more. By understanding and properly handling the “overload resolution failed” cases, you can unlock the full potential of createObjectURL() across browsers.