Device Status
View the status of your phone or computer: battery, memory, processor, screen and network, with a speed test. Everything stays in your browser.
Everything you see here is read directly from your device by your browser. Nothing is sent and nothing is saved: close the page and everything is gone.
Speed test
Measure how fast this device's processor calculates: first with one core, then with all cores at once. This takes about 4 seconds and the device may get warm or slow for a moment. A higher number is faster. Compare devices by running the same test, and preferably run it twice.
What does your browser share?
For privacy reasons, browsers don't share everything. Here you can see what this browser does reveal.
A website cannot see how much memory your device is actually using, how hard the processor is working right now, which apps are open, or how much storage is available. This is deliberately hidden. What you see here are the things browsers do share: the battery (only in Chrome and similar browsers), a rounded memory amount (same), the number of processor cores, the display, the network, and an indication of how smoothly this page is running.
Processor load cannot be measured directly. The page does measure how often it's woken up late: if it's lagging, the device is busy. This indicates activity while you're on this page, not for the whole device.
Where do you find the real numbers on an iPhone?
At Settings → Battery you can see battery usage per app and battery health. At Settings → General → iPhone Storage you can see how much space is available. Names may vary by version.
And on an Android phone?
Look at Settings → Battery for battery usage and at Settings → Storage for available space. Many brands also have a "Device care" section with memory and processor information. Names vary by brand and version.
This type of data could also be used to identify a device, which is why browsers mask some values. Want to know what a website sees about your connection? Use What is my IP? or the HTTP headers tool.