Your PC Has a Check Engine Light — This Free Website Is It

 Your keyboard has a dead key you never noticed. Your mouse's polling rate is nowhere near the 1000Hz the box promised. Your monitor has a stuck pixel hiding in the top-right corner. And your controller? It's been drifting so slowly you've been compensating for it without realizing.

The worst part is you can't diagnose any of this without downloading sketchy software, installing drivers, or buying dedicated hardware testers that cost more than the peripherals themselves. My PC Tester flips that entire equation. It's a browser-based diagnostic suite that runs every major PC peripheral test you can think of — no installation, no account, no hidden data collection. Just open the page and start pressing keys.

What It Actually Tests

The site covers a genuinely surprising range of hardware, and the depth on each front is what separates it from the usual "press any key" browser toys.

Keyboard Diagnostics. The keyboard tester renders a 1:1 visual replica of your physical layout, and every key lights up the moment it registers a signal. Dead keys, stuck keys, chatter (where a single press registers as multiple inputs), and ghosting issues all become instantly visible. This is the kind of tool that turns a frustrating intermittent problem into a five-second diagnosis.

Mouse Performance Testing. Click every button, scroll through the wheel in both directions, and watch the live polling rate readout as you move the cursor. The site measures your mouse's actual Hz in real time — if you've got a 1000Hz gaming mouse that's only registering at 125Hz through a cheap USB hub, you'll see it immediately. It also flags double-click issues on the microswitches, which is the most common failure mode on aging mice.

Monitor Inspection. Dead pixels, stuck pixels, backlight bleed, color banding, and uniformity issues are all testable through full-screen test patterns. The tool lets you cycle through solid colors, gradients, and checkerboard patterns to surface defects you'd otherwise never spot during normal use.

Gamepad and Controller Testing. Stick drift is the silent killer of controller longevity. The gamepad tester visualizes each analog stick's input range in real time, so you can see exactly how much ghost input your worn-out sticks are registering when they should be at rest. Button presses, trigger travel, and vibration motors are all covered.

Microphone and Audio Analysis. The site includes a real-time spectrum analyzer that visualizes your microphone's frequency response. This is useful for checking whether your mic is actually capturing the full range it claims, or if it's cutting off lows or highs you'd want for voice work or streaming.

GPU and WebGL Stress Testing. A browser-based GPU stress test pushes your graphics card through WebGL workloads to check for stability issues, thermal throttling, and rendering artifacts. It's not a replacement for a dedicated benchmarking suite, but it'll surface instability fast.

Who Built This, and Why It Matters

My PC Tester is the work of a solo developer who previously built CPU Rank List, a popular CPU comparison site. The developer has been transparent about the project's origins — it went through multiple rebuilds before reaching a state he was satisfied with, and the final version was developed with heavy AI assistance.

That backstory matters for one practical reason: this isn't a corporate product trying to upsell you into a premium tier. There's no "Pro" version waiting behind a paywall. The entire suite is free, and the developer's stated motivation was filling a gap he noticed while working on his CPU comparison tool — people needed a quick way to test peripherals without installing a bunch of one-off utilities.

The Privacy Angle

Browser-based testing tools live or die on trust. A site that asks you to press every key on your keyboard and click every mouse button could, in theory, be logging everything. My PC Tester sidesteps that concern by running entirely client-side. Your input data never leaves your machine. No account, no tracking, no telemetry.

For anyone who's ever hesitated to run a random "keyboard tester" from a search result, that distinction is worth noting.

The Bottom Line

My PC Tester isn't flashy. It doesn't have a slick marketing page or a subscription model. What it has is a comprehensive set of hardware diagnostics that actually work, running in a browser tab, free of charge. Whether you're a system builder checking a fresh build for faulty components, a gamer trying to figure out why your aim feels off, or just someone who suspects their monitor has a dead pixel and wants confirmation before filing a warranty claim, it's worth having bookmarked.

You can try it yourself at My PC Tester.