🟢 100% Free — No Signup
Free PC Diagnostic Tools
Not just pass/fail testers — these tools measure jitter, stability, and consistency, explain what the numbers actually mean, and are upfront about what a browser can and can't measure. Test your keyboard, mouse, and monitor instantly, no downloads required.
🚫 No downloads 🔒 Runs locally in your browser ⚡ Instant results 🆓 100% free, no signup
Full 104-Key Test
Keyboard Tester
Test every key on your full-size keyboard including numpad, arrows, and function keys. Measures fastest key response live in your browser.
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Up to 8000Hz Mouse Rate Test
Check your mouse's browser-observed polling rate, click latency, jitter, and movement speed. Includes a live heatmap and CPS counter, with JSON/CSV export for deeper analysis.
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Live Hz + Grade Monitor Refresh Rate Test
Measure your screen's browser-observed refresh rate and frame consistency with a stability grade. Includes a motion clarity test and a VRR/G-Sync simulator to see the difference.
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Dead Pixel + Color Screen Test
Check for dead/stuck pixels, backlight bleed, color accuracy, motion blur, and text sharpness — plus a one-click Full Screen Health Check that runs the full sequence automatically.
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Live FPS + Audio Webcam/Mic/Speaker Test
Check your webcam's live FPS, light and focus, mic waveform with clipping detection, and a full left/right speaker channel test — all in one place.
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Not Sure What's Wrong?
Don't know if it's a hardware fault or a settings issue? Follow this in under 2 minutes.
1
Choose Your Device
Keyboard, mouse, or monitor — pick whichever one is acting up.
2
Run the Test
Usually done in under 60 seconds. No download, runs right in your
browser.
3
Understand the Result
Every metric is explained — good, needs investigation, or a known
browser limitation.
4
Fix the Problem
Follow the linked guide to fix a setting, or confirm it's genuinely a
hardware issue.
⌨️ Start with Keyboard 🖱 Start with Mouse 🖥️ Start with Monitor 🟦 Start with Screen 🎙️ Start with Webcam
What Makes These Tools Different
Most online testers give you one number and stop there. Ours are built to be measurement instruments, not just pass/fail checkers.
📊 Real statistics, not just averages
Jitter, peak vs average, stability grading, min/max intervals — the
numbers that tell you whether a reading is trustworthy.
🎯 Honest about browser limits
We tell you upfront where browser throttling affects a reading,
instead of presenting every number as gospel.
📤 Exportable results
Download your session as JSON or CSV to compare devices or track
changes over time — not locked in a single screen.
🔒 Nothing leaves your device
Every test runs fully client-side. No signup, no accounts, no data
sent anywhere.
How Accurate Are These Tests?
Every browser-based test has real limits — event coalescing, OS scheduling, and background CPU load can all affect a reading. We'd rather explain that than hide it behind a single impressive-looking number.
⌨️ Keyboard
Physical key → OS → browser event → measured press duration.
Reliable for comparing keys against each other; not a substitute for
a hardware scan-rate spec.
🖱 Mouse
Mouse → OS → browser pointer events (using getCoalescedEvents where
supported) → statistical analysis. Reliable up to roughly
1500–2000Hz in most Chromium browsers; higher rates can be
under-reported.
🖥️ Monitor
Display → requestAnimationFrame → frame-timing analysis. Accurate to
roughly ±1–2Hz under normal conditions, with a stability grade to
flag when a reading isn't holding steady.
🟦 Screen
Full-screen reference colors and patterns — the same principle used
by dedicated dead pixel checkers. A browser can't read back what's
physically displayed, so spotting a dead pixel or backlight bleed
still needs your own eyes; this tool gives you the cleanest possible
reference to check against.
🎙️ Webcam/Mic/Speaker
Camera → MediaStream track settings + live frame timing for FPS. Mic
→ Web Audio API for relative level, noise floor, and clipping — not
a calibrated decibel reading. Speakers → real hard-panned tones per
channel, so what you hear is exactly what's being sent.
Common Problems These Tools Help You Diagnose
Keys not registering or repeating
Stuck keys, double inputs, or dead zones on your keyboard? Test
every key individually before assuming it's a hardware failure.
Cursor feels laggy or inconsistent
Verify your mouse is actually hitting its rated polling rate — many
"gaming" mice ship running below spec out of the box.
Monitor not showing full refresh rate
A 144Hz monitor plugged in wrong (cable, port, or Windows setting)
often silently runs at 60Hz. Confirm what you're actually getting.
Dead pixels or backlight bleed
Spotted a dark or oddly-colored dot on your screen? Run the full
color sequence to confirm whether it's a dead pixel, a stuck pixel,
or just glare.
Webcam, mic, or speaker acting up
Blurry video calls, a mic that sounds distorted, or audio playing
from the wrong speaker — check FPS, clipping, and channel routing
before assuming the hardware is faulty.
Buying a used or refurbished PC
Before buying secondhand hardware, run a full check on the keyboard,
mouse, display, and webcam — takes under a minute per device.
Why Test Online Instead of Calling a Technician?
Most keyboard, mouse, and monitor issues aren't hardware failures — they're driver conflicts, wrong Windows settings, or a cable running below spec. Testing in-browser first means you skip the diagnostic fee and know exactly what's wrong before spending money on a repair or replacement.
Want to Understand the Numbers?
Run a test, then read the full breakdown of what scan rate, polling rate, and system latency actually mean for your setup.
Keyboard Latency Guide →
Scan rate vs polling rate vs system latency, explained with real
formulas and examples.
Mouse Polling Rate Guide →
What jitter means, why browsers under-report high-Hz mice, and how
to read a stability score.
Backlight Bleed & Dead Pixel Guide →
Step-by-step method to check any screen for bleed, dead pixels, and
stuck pixels before you buy or return it.
Monitor Refresh Rate Guide →
How to confirm your monitor is actually running at its rated Hz, and
what the stability grade means.
Webcam/Mic/Speaker Guide →
What FPS, light level, noise floor, and clipping actually mean, and
how to fix the most common camera/mic/speaker problems.
Full Testing Methodology →
How requestAnimationFrame, Pointer Events, and coalesced events work
— and exactly where browser-based testing hits its limits.
Frequently Asked Questions
Is my data uploaded or stored anywhere?
No. Every test runs locally in your browser. Key presses, mouse
movement, and refresh-rate measurements never leave your device or
get sent to any server.
Why does my 1000Hz mouse show a lower polling rate in the test?
This is a browser limitation, not a problem with your mouse.
Browsers typically throttle input event updates to conserve battery
and CPU, so a 1000Hz mouse may display 60–120Hz in-browser even
though the hardware is reporting correctly at full rate.
Why is my keyboard stuck at 125Hz even on a gaming keyboard?
Standard office and budget keyboards are hardware-locked to 125Hz
regardless of software settings. Only keyboards explicitly marketed
with 1000Hz+ polling (common in gaming keyboards) can exceed this —
check your keyboard's spec sheet to confirm.
Are these tests actually accurate, or just an estimate?
Browser-based tests measure input as it reaches your operating
system — through the same path any game or app would receive it.
This makes them highly reliable for comparison purposes, though a
browser can't bypass OS-level polling limits. For example, most
browsers cap visual updates around 60–120Hz, so a 1000Hz mouse may
show a lower number even when the hardware itself is working
correctly.
Do I need to install anything to use these tools?
No. All five tools run entirely in your browser using native web
APIs — nothing is installed, and no drivers are required.
Do these tools work on laptops and trackpads?
Yes — the keyboard and mouse testers work with built-in laptop
keyboards and trackpads as well as external peripherals, on any
modern browser.
Which browser gives the most accurate results?
Chromium-based browsers (Chrome, Edge) generally expose the most
precise timing APIs for polling-rate and refresh-rate measurement.
Firefox and Safari work fine too, but numbers can vary slightly
between browsers due to differences in event throttling.
Can these tools detect a faulty or dying peripheral?
Yes, indirectly. Inconsistent jitter on the mouse test, keys that
fail to register on the keyboard tester, or a refresh rate that
won't hold steady on the monitor test are all signs worth
investigating further — often before assuming you need a
replacement.
Can I check for dead pixels before buying a laptop?
Yes — run the Screen Test's Full Health Check in a dark room at full
brightness. It cycles through black, white, and color screens so you
can spot dead or stuck pixels and backlight bleed in under a minute.
Can this tool tell if my webcam or mic is actually broken?
It can rule out a lot of false alarms — no signal at all usually
means a permissions or device-selection issue, not broken hardware.
Persistent clipping, a stuck-low FPS in good light, or audio from
the wrong speaker channel are stronger signs worth investigating
further.