[Web] Ort tries (and fails) to fetch an .mjs file from localhost when imported through importScripts() using a CDN url in a web worker

[andynewman10]

Describe the issue

I can succesfully use the ONNX runtime on the web from my main web page, using the following CDN URL and an async SCRIPT tag:

https://cdn.jsdelivr.net/npm/onnxruntime-web@1.20.1/dist/ort.all.min.js

Execution providers such as WASM or WebGPU are working fine.

However, when I do exactly the same thing from a web worker, using importScripts, the importScripts statement runs fine, but the promise returned by ort.InferenceSession.create cannot be waited for - instead, an error happens (see below).

I am not sure what to do at this point. Is this a bug or is this limitation a by-design limitation of web workers? Shall I just host all ORT files on my web server?

My setup:

• Windows 11 24H2
• same result with both Chrome 134 or Edge 135.
• nVidia GTX 1060 GPU with latest drivers

To reproduce

From a web worker:

importScripts("https://cdn.jsdelivr.net/npm/onnxruntime-web@1.20.1/dist/ort.all.min.js"); // succeeds
let onnxRT = ort.InferenceSession.create("http://localhost:7500/model.onnx", {'executionProviders': ['webgpu']}); // succeeds
let awaited = await onnxRT ; // does not succeed

The error is:

http://localhost:7500/ort-wasm-simd-threaded.jsep.mjs
Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html". Strict MIME type checking is enforced for module scripts per HTML spec.

no available backend found. ERR: [webgpu] TypeError: Failed to fetch dynamically imported module: http://localhost:7500/ort-wasm-simd-threaded.jsep.mjs

(here it basically says it cannot fetch the resource, this is not a MIME type issue).

Urgency

No response

ONNX Runtime Installation

Released Package

ONNX Runtime Version or Commit ID

See above CDN url.

Execution Provider

'webgpu' (WebGPU)

[andynewman10]

Resolving my own issue... A fix for this problem is provided here: #16102 (comment)