Tools
The checks worth running the day new gear arrives. No install — they run in the browser.
Monitor color matching (dual monitors)
Set brightness, contrast and gamma by eye, and bring two monitors into agreement side by side.
Dead pixel test (backlight bleed)
Find dead pixels and backlight bleed with full-screen solid colors. Do it inside the return window.
Keyboard test (dead keys, N-key rollover)
Check for dead keys, keys that fire on their own, and your simultaneous-press limit.
Typing speed test (words per minute)
Words per minute and accuracy together. Also useful for comparing two keyboards.
Mouse double click test (switch chatter)
Check switch chatter (the double-click symptom), polling rate, and button and wheel behaviour.
Earbud left/right test (one side silent)
Left and right channels, balance, and the frequency range you can actually hear.
Image compressor (reduce photo size)
Shrink image files right in the browser. Nothing is uploaded.
Image watermark (logo or text on photos)
Put the same logo or text on many photos in one run. Nothing is uploaded.
HEIC converter (iPhone photos to JPG/PNG)
Convert iPhone photos (HEIC) to JPG, PNG or WebP. Batch to ZIP in one go.
Start from the symptom
The expensive mistake with faulty gear is deciding on a replacement or a warranty claim before you know whether it is actually broken. A key that looks dead can be the cable or the USB hub rather than the keyboard, and a cursor that stutters is more often the receiver's position or battery voltage than the mouse. Pick the symptom below, spend thirty seconds with the matching tool, and you will know which side the problem is on.
| Symptom | Tool to try first |
|---|---|
| A key does not register, or fires on its own | Keyboard test (dead keys, N-key rollover) |
| One press registers as two | Mouse double click test (switch chatter) |
| The cursor pauses, then jumps | Mouse double click test (switch chatter) |
| Only one earbud plays, or the channels feel swapped | Earbud left/right test (one side silent) |
| A new monitor shows a dot, or the edges glow | Dead pixel test (backlight bleed) |
| Two monitors disagree on color | Monitor color matching (dual monitors) |
What these tools cannot do
None of this is lab equipment. A number measured in a browser has passed through the operating system and the browser first, so it is normally lower than the manufacturer's figure. Treat the readings as "roughly this class" rather than absolute values, and use the vendor's own utility when you need precision. Dead-pixel exchange thresholds are also set separately by each retailer and manufacturer — once a tool finds one, check the policy that actually applies to your purchase.
Nothing is uploaded
Every tool runs inside the browser. Keystrokes, click timings and images never reach a server, and there is no sign-up and nothing to install. Image compression works the same way — the browser does the work rather than sending your file anywhere.