DEVCHECKI

* Uses Cloudflare speed endpoints with 4 parallel download / 3 parallel upload streams (same method as professional speed tests). The test transfers data for ~16 seconds — on fast connections this can use 100+ MB, so avoid running it repeatedly on metered mobile data.

Plays a tone on the left, then right, then both — just listen. Or tap a speaker below to test one side.

Pick any pitch from deep bass (20 Hz) to the limit of hearing (20 kHz). Drag while playing — the pitch changes live.

Plays a rising tone from 20 Hz to 16 kHz over ~15 seconds. You should hear a smooth, continuous rise — if the sound disappears in places, your speakers can't reproduce those frequencies (small speakers often lose deep bass below ~100 Hz; that's normal).

▶ START SWEEP

⚠ Some keys cannot be detected by browsers: Win/Meta (OS intercept), Fn (hardware-only), Print Screen, Pause/Break, and some media keys — this is a browser security restriction, not a hardware issue.

* Touch support is detected via browser APIs. Some laptops show touch points > 0 even without a touchscreen (HID emulation).

Rapidly cycles colors across the whole screen to exercise stuck sub-pixels — run for 10–20 minutes. Works on stuck pixels (showing one fixed color); truly dead (black) pixels are a hardware fault and can't be revived. ⚠️ Contains rapidly flashing colors — do not use if you are sensitive to flashing lights.

* Browsers only expose gamepads after a button press (privacy requirement). Press every button to fully test the controller.

Two phases of ~4 seconds each: first one core at full load, then all cores together. Higher scores are better. Close heavy apps for a fair result — and expect a brief fan spin-up, that's the point.

* Browser benchmarks measure relative performance — useful for comparing devices or spotting throttling, not identical to native benchmark scores.

Runs all CPU cores and the GPU at 100% simultaneously. Performance is sampled every 2 seconds — if it falls significantly below the starting level, the machine is thermal-throttling. Perfect after a repaste, fan replacement, or to verify a "random shutdown" complaint. Browsers can't read temperature sensors directly, so sustained performance under load is the honest proxy. Expect loud fans and a hot chassis — that's the test working.

These sensors exist on phones and tablets — on a desktop PC this test will report "not available", which is normal. On iPhone/iPad you'll be asked for motion permission first. Tilt the device to move the bubble level, rotate it to spin the compass.

Test the rest of your phone's sensors. Some need a tap to start (location, vibration); availability varies by device and browser.

Shows what any website can see about you. Nothing runs until you click — the IP lookup queries ipapi.co once from your own browser. If you use a VPN, this is the page that tells you whether it's actually hiding you.

Generated locally with your browser's cryptographic randomness — never sent anywhere, never stored.