Live Screen Refresh Rate Test (Hz), Frame Time & Motion Clarity Checker (2026)

Measure your monitor or smartphone screen's real-time refresh rate (60Hz, 90Hz, 120Hz, 144Hz, 240Hz), frame-time jitter (ms), and motion persistence using requestAnimationFrame.

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Live 120Hz/144Hz/240Hz Display Refresh Rate & FPS Tester — Interactive Console

Runs locally in your browser • Instant output

Live Refresh Rate

60 Hz / FPS

60Hz Standard

Avg Frame Time

16.67 ms

1000ms / 60fps

Min Frame Delta

16.2 ms

Max Frame Delta

17.1 ms

Live Motion Smoothness Track (Orange = Native Hz • Gray = Simulated Stepped Cadence)

Dead & Stuck Pixel RGBW Inspector (Click to Cycle Colors)

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<a href="https://www.zerosuniverse.com/tools/display-refresh-rate-hz-tester/">Live 120Hz/144Hz/240Hz Display Refresh Rate & FPS Tester — ZerosUniverse</a>

2026 Quick-Reference Cheat Sheet & Benchmark Table: Live 120Hz/144Hz/240Hz Display Refresh Rate & FPS Tester

Quick Answer & 2026 Technical Summary (screen refresh rate test hz)Updated 2026 Standard

Three common reasons: (1) Battery Saver / Low Power Mode is active on your laptop or phone, which forces browsers to 60Hz; (2) Windows/macOS Display Settings -> Advanced Display is still set to 60Hz; or (3) Hardware Acceleration is disabled in browser settings. Use this interactive screen refresh rate test hz above to test 120hz 144hz monitor test online, fps frame time checker, and dead pixel test screen locally in your browser with zero server uploads.

Target Keyword Spec: screen refresh rate test hz  |  Modules: High-Precision requestAnimationFrame Hz Counter • Dual Native Hz vs 60fps Motion Comparison Track • Frame-Time Stability & Stutter Detector

Primary Focus: screen refresh rate test hz

Core Capability: 120hz 144hz monitor test online

Privacy Mode: 100% Client-Side (Zero Upload)

Technical Parameter / Module	Standard / Keyword Spec	Architecture & Validation Rule	Operational Use Case (2026)
High-Precision requestAnimationFrame Hz Counter	`120hz 144hz monitor test online`	Samples sub-millisecond DOMHighResTimeStamp deltas over a rolling window to...	Verifying 120Hz/144Hz Gaming Monitor & Phone Settings
Dual Native Hz vs 60fps Motion Comparison Track	`fps frame time checker`	Renders two synchronized gliding motion bars (full native refresh rate vs l...	Inspecting New Monitors & Laptops for Dead Pixels
Frame-Time Stability & Stutter Detector	`dead pixel test screen`	Calculates average frame time (e.g., 8.33ms at 120Hz) and flags dropped fra...	Verifying 120Hz/144Hz Gaming Monitor & Phone Settings
Hardware & Protocol Spec Version	`2026 IEEE / JEDEC / VESA / PCI-SIG`	High-Precision Browser API Telemetry	Cross-checked against hardware datasheets
Real-Time Measurement Loop	`requestAnimationFrame / WebAudio / WebGL`	Sub-Millisecond HighResTimeStamp (DOMHighRes)	Runs natively on desktop, laptop & mobile browsers
Safety Headroom & Efficiency Factor	`80 PLUS / PFC 0.8–0.9 / 25% Surge Margin`	Continuous Load ≤ 75% Rated Peak Capacity	Prevents thermal throttling & voltage droop

In-Depth ZerosUniverse Tutorial

10 Best Gaming Browsers in 2026

Read our complete step-by-step editorial guide, architecture breakdown, and defensive best practices on ZerosUniverse.

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How to Use Live 120Hz/144Hz/240Hz Display Refresh Rate & FPS Tester

Close Heavy Background Tabs

Ensure Battery Saver / Low Power Mode is turned off so your browser is not throttled to 30fps or 60fps.

Observe Live Measured FPS & Estimated Display Hz

Watch the real-time counter stabilize over 2–3 seconds to show your active refresh tier and frame time (ms).

Compare the Native Hz vs 60fps Motion Tracks

Watch the moving comparison markers to verify high-refresh motion clarity.

Optional: Run Dead Pixel Swatch Test

Click any color swatch to inspect your panel fullscreen (click anywhere or press ESC to exit).

Key Capabilities & Technical Architecture

High-Precision requestAnimationFrame Hz Counter

Samples sub-millisecond DOMHighResTimeStamp deltas over a rolling window to detect 60Hz, 75Hz, 90Hz, 120Hz, 144Hz, 165Hz, 240Hz, and 360Hz.

Dual Native Hz vs 60fps Motion Comparison Track

Renders two synchronized gliding motion bars (full native refresh rate vs locked 60fps/30fps) so you can visually see the smoothness difference.

Frame-Time Stability & Stutter Detector

Calculates average frame time (e.g., 8.33ms at 120Hz) and flags dropped frames or Low Power Mode throttling.

Built-In Dead Pixel Color Cycle Inspector

Includes 1-click Red, Green, Blue, White, and Black fullscreen color swatches to spot stuck or dead pixels.

Practical Use Cases

Verifying 120Hz/144Hz Gaming Monitor & Phone Settings

Confirm that Windows Display Settings or Android Adaptive Smoothness isn't locking your browser to 60Hz.

Inspecting New Monitors & Laptops for Dead Pixels

Cycle solid RGB color backgrounds before your return window expires.

Frequently Asked Questions (FAQs)

Why does my 120Hz or 144Hz screen only show 60Hz in the browser?+

What is frame time in milliseconds (ms)?+

Frame time is the duration each frame remains on screen (1000 / Hz). At 60Hz, each frame takes 16.67ms; at 120Hz it takes 8.33ms; and at 240Hz it takes just 4.17ms.

How does requestAnimationFrame measure screen refresh rate?+

The W3C window.requestAnimationFrame API fires a callback synchronized directly with the display's vertical blanking interval (VSync), allowing precise measurement of hardware refresh cycles.

Why does Safari on iPhone/Mac sometimes cap requestAnimationFrame at 60fps?+

On ProMotion (120Hz) Apple devices, Safari defaults page animations to 60fps unless Prefer Page Rendering Updates near 60fps is unchecked in Feature Flags or smooth high-frequency scrolling is active.

What is the difference between a dead pixel and a stuck pixel?+

A dead pixel stays permanently black across all color swatches because its transistor receives no power, whereas a stuck pixel remains lit in a single sub-pixel color (red, green, or blue).