WebNN & NPU Test
Can your browser run AI on your own hardware? This test probes WebNN contexts for your CPU, GPU and NPU, live.
Not tested yet
One click asks your browser to create WebNN contexts on each processor type. Everything runs on your device.
Context Results
Live inference demo (adds 10+1, 20+2, 30+3, 40+4 on your hardware)
Not run yet
What is WebNN?
WebNN, the Web Neural Network API, is a W3C standard for running machine-learning models in the browser, directly on the user's hardware. Instead of a website shipping your photo or document to a cloud AI and waiting, the model executes locally on the CPU, the GPU, or a dedicated neural processing unit. For developers that means no inference bill and no upload queue. For users it means AI features that work offline and keep private data on the device.
The standard reached W3C Candidate Recommendation status and is landing browser by browser, which makes this an awkward and interesting moment: your chip may already carry an NPU while your browser cannot use it yet, or the reverse. This test separates those layers by asking for each context type explicitly and then, where possible, proving the pipeline end to end with a tiny real inference.
CPU, GPU or NPU: what is the difference?
A CPU context always exists but is the slowest route for neural math. A GPU context uses your graphics chip, typically far faster for models, and is the workhorse of browser AI today. An NPU context uses the neural block in newer processors (Snapdragon X, Intel Core Ultra, AMD Ryzen AI, Apple M-series): not always the fastest, but dramatically more power-efficient, which is why laptops market AI battery life around it. A site that supports WebNN can pick the best context your device offers.
If your test fails
Update your browser first, then your graphics and chipset drivers. On Chromium browsers, WebNN may still sit behind a flag: visit chrome://flags, search "WebNN", enable it, and restart the browser. Windows currently has the deepest support because Chromium routes WebNN through DirectML there. A fail is a snapshot of today's software state, not a judgment on your hardware: retest after browser updates, because this API is moving fast.
How to use this test
- Click Test My Device for WebNN. No permission prompt is needed.
- Read the context table: a green row means your browser created a working WebNN context on that processor.
- If any context succeeds, the page runs a tiny inference on it and shows the computed answers as proof.
- Use Copy Full Report to save the result for bug reports or comparisons across your devices.
Frequently Asked Questions
What is WebNN?
WebNN, the Web Neural Network API, is a W3C standard that lets websites run machine-learning models directly on your hardware: CPU, GPU, or a dedicated neural processing unit (NPU). Models run locally in the browser, so nothing needs to be sent to a cloud server, which makes browser AI faster, cheaper to serve, and private by design.
What is an NPU and do I have one?
An NPU (neural processing unit) is a chip block built specifically for AI math, found in recent processors such as Qualcomm Snapdragon X, Intel Core Ultra, AMD Ryzen AI and Apple M-series chips. This test asks your browser for an NPU context directly: if one is created, your device has an NPU the browser can use. If not, your chip may still have one that the browser cannot reach yet.
Which browsers support WebNN?
WebNN is a W3C Candidate Recommendation and is still rolling out. Chromium-based browsers lead: recent Chrome and Edge builds expose it on Windows, backed by DirectML, with the strongest support on Copilot+ PCs. Other browsers and platforms are at earlier stages. Because availability changes build by build, this page probes your actual browser rather than relying on a chart.
Why does every context fail on my machine?
The usual reasons are a browser build without WebNN enabled, an operating system without the DirectML or equivalent runtime, or drivers that are too old. On Chromium browsers WebNN can also sit behind a flag: open chrome://flags, search for WebNN, enable it and restart. Support is expanding quickly, so a fail today is a snapshot, not a verdict on your hardware.
Is anything uploaded during this test?
No. The context checks and the tiny inference demo run entirely on your device with the WebNN API. That is the point of WebNN itself: AI that never leaves your machine. Cubbbix sees none of your results unless you copy the report and share it yourself.
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