QUALITY
Measured Cadence: — Hz
Target Classification: 60 Hz Standard
How Refresh Rate Testing Works
Core Concepts
- Browser vs Native Settings: Browser rendering generally follows the display configuration exposed by the operating system and compositor. Ensure your target refresh rate is configured in system display settings.
- Power Throttling: Unplugged laptops or battery saving modes may reduce refresh rate or system performance depending on the laptop and power profile.
- Cadence Jitter: Pacing jitter measures deviations from the expected frame interval. Lower jitter indicates uniform, smooth frame delivery.
100% Client-Side Privacy
- Local Execution: All timing metrics and variance calculations execute strictly in your local browser window.
- Private Storage: Your historical measurements remain securely on your local device.
What Is Monitor Refresh Rate?
Understanding Display Hz and Frame Intervals
A monitor's refresh rate, expressed in Hertz (Hz), defines how many times per second the display panel redraws its complete visual raster buffer with new frame data. On a standard 60Hz screen, the display refreshes 60 times each second, producing a new scanout every 16.67 milliseconds. On a 144Hz gaming monitor, the screen updates 144 times every second, reducing the frame interval down to 6.94 milliseconds.
Refresh rate sets the upper ceiling for how many distinct temporal frames a display can physically present. However, having a high refresh rate does not automatically force software or games to generate frames faster; your graphics card (GPU) must also render frames at an equivalent pace to take full visual advantage of the panel's cadence.
Number of raster scanout cycles per second.
Time budget allotted to each individual frame.
Smaller visual jumps between consecutive frames.
How to Test Your Monitor Refresh Rate
- Keep Test Tab Active: Maintain this browser window focused to avoid background timing throttling.
- Select Duration: Pick Quick (3s), Standard (10s), or Stability (30s).
- Start the Test: Click Start Refresh Rate Test to begin sampling high-resolution timestamps.
- Allow Calibration: The engine syncs the viewport baseline over the first several animation frames.
- Analyze Rolling Metrics: Check Current Rate, Rolling Average, Frame Jitter, and Delayed Frames.
- Verify Stability Score: Review the final pacing grade and target classification against your system settings.
Display Refresh Rate Standards Reference
Display Hz, Frame Time & Perceptual Characteristics
Mathematical frame duration is calculated using the exact formula Frame Time (ms) = 1000 / Hz.
| Refresh Rate | Frame Interval (ms) | Time Saved vs 60Hz | Primary Category | Perceived Motion & Practical Value |
|---|---|---|---|---|
| 60 Hz | 16.67 ms | Baseline (0.00 ms) | Standard Display | Standard for general office work, web browsing, video streaming, and console gaming. |
| 75 Hz | 13.33 ms | -3.34 ms | Entry Productivity | Subtle fluidity bump over 60Hz; widely found on budget office monitors. |
| 90 Hz | 11.11 ms | -5.56 ms | Mobile & Smooth Baseline | Popular on modern smartphones, ultrabooks, and entry VR headsets for smooth touch scrolling. |
| 120 Hz | 8.33 ms | -8.34 ms | High Refresh Baseline | Doubles 60Hz temporal resolution. Drastically improves UI fluidity, touch tracking, and gaming responsiveness. |
| 144 Hz | 6.94 ms | -9.73 ms | Common Gaming Use | Common high-refresh standard for PC gaming displays. Sharp reduction in eye-tracking motion blur. |
| 165 Hz | 6.06 ms | -10.61 ms | High-Refresh Gaming | Common native or factory-overclocked tier on modern IPS and Fast VA gaming panels. |
| 180 Hz | 5.56 ms | -11.11 ms | High-Speed Gaming | Increasingly standard on value 1080p and 1440p gaming displays with modern scalar hardware. |
| 240 Hz | 4.17 ms | -12.50 ms | Very High Refresh | Extremely rapid scanout rate favored in fast-paced competitive games and shooters. |
| 360 Hz | 2.78 ms | -13.89 ms | Extreme High Refresh | Ultra-low frame interval for competitive tracking; requires high-end CPU/GPU systems. |
| 480 Hz | 2.08 ms | -14.59 ms | Cutting-Edge High Refresh | Cutting-edge OLED and high-speed monitors; minimizes sample-and-hold persistence. |
Head-to-Head Refresh Rate Comparisons
60Hz vs 120Hz: The Biggest Visual Leap
Δ 8.34 msMoving from 60Hz (16.67ms) to 120Hz (8.33ms) cuts frame duration in half, eliminating 8.34 milliseconds of display lag per refresh cycle. This is widely considered the most dramatic and easily noticeable jump in display technology.
- Perceptual Impact: Cursor movement, document scrolling, and camera panning feel immediately more connected.
- Workload Demand: Requires the GPU to output 120 frames per second for synchronized fluidity.
120Hz vs 144Hz vs 165Hz: Mainstream Gaming
Δ 1.39 ms & 0.88 ms144Hz (6.94ms) and 165Hz (6.06ms) represent incremental refinements over 120Hz. While 144Hz saves an additional 1.39ms per frame and 165Hz saves another 0.88ms, the difference between these three tiers is subtle.
- Perceptual Impact: Noticeable in fast camera sweeps, but far less pronounced than the 60Hz → 120Hz leap.
- Hardware Sweet Spot: Ideal balance between graphical fidelity and achievable frame rates on modern GPUs.
144Hz vs 240Hz: Diminishing Returns vs Esports
Δ 2.77 msJumping from 144Hz (6.94ms) to 240Hz (4.17ms) saves 2.77 milliseconds per frame cycle. Due to the law of diminishing marginal returns in temporal resolution, 240Hz is best appreciated in competitive, high-motion titles like tactical shooters and racing simulators.
- Perceptual Impact: Clearer target tracking during rapid flick shots and high-velocity panning.
- System Load: Demands robust CPU single-thread speed and fast GPU memory to sustain ~240 FPS.
240Hz vs 360Hz & 480Hz: Elite Tier
Δ 1.39 ms & 0.70 msMoving to 360Hz (2.78ms) and 480Hz (2.08ms) enters the realm of micro-millisecond gains. These extreme display rates are engineered specifically for professional esports athletes seeking the absolute minimum display-side presentation interval.
- Perceptual Impact: Near-instantaneous visual feedback; near-zero sample-and-hold motion persistence.
- Requirement: Requires optimized esports engines capable of rendering 360–500+ FPS continuously.
Refresh Rate (Hz) vs Frame Rate (FPS)
What Is the Difference?
While frequently used interchangeably in casual discussion, Refresh Rate (Hz), Delivered Browser Cadence, and Frame Rate (FPS) measure distinct stages of the visual pipeline:
- Refresh Rate (Hz): Hardware property or configured operating mode of your monitor indicating how many times per second the display panel can present visual updates.
- Browser Delivered Cadence: What this tool observes in real time via
requestAnimationFrame, reflecting actual frame delivery to the active viewport. - Frame Rate (FPS): Software and rendering throughput measured by tools like our FPS Checker, indicating how many complete frames your GPU renders each second.
Can FPS Exceed Refresh Rate?
Yes. Your GPU can render 300 FPS even if your monitor refreshes at 144Hz. In this scenario, the graphics card renders frames faster than the screen can show them whole. Depending on your synchronization mode:
- Uncapped / V-Sync Off: Display displays multiple partial frames in one scan, causing horizontal screen tearing but delivering fresher input data.
- V-Sync / G-SYNC / FreeSync: Frame presentation is coordinated to eliminate tearing while regulating frame delivery.
Four Common Refresh Rate & Frame Rate Scenarios:
The screen can only present 60 full updates per second. Excess rendered frames are dropped or torn across scanlines.
Each rendered frame is held or duplicated across 2.4 refresh cycles. Perceived motion remains limited to a 60 FPS baseline.
Perfect 1:1 synchronization. Every monitor refresh cycle displays a newly rendered frame with maximum smoothness and uniform cadence.
Without VRR (FreeSync/G-SYNC), irregular frame duplication can create micro-stutter. With VRR, the monitor modulates its scanout to 100Hz.
Frame Time, Pacing, Jitter & Stutter
What Is Frame Time?
Frame time is the duration in milliseconds required to generate and present one single frame. While average FPS summarizes total throughput over a full second, frame time measures the real-time heartbeat of each visual update.
60Hz → 16.67ms | 144Hz → 6.94ms
What Is Frame Pacing?
Frame pacing describes how evenly frames are spaced over time. If a game renders 60 frames in one second, but delivers 30 of them in the first 200ms and the remaining 30 over 800ms, the motion will feel stuttery despite displaying a nominal "60 FPS" average.
Consistent frame pacing ensures that every frame interval matches the target refresh period with minimal standard deviation.
Frame Jitter & Stutter
Frame jitter measures rapid millisecond fluctuations between consecutive frame intervals. When frame times suddenly spike from 6.9ms up to 25ms due to background CPU tasks or compositor pauses, users perceive a momentary hitch or micro-stutter.
Our tool calculates frame jitter to quantify how smoothly and consistently your browser compositor presents frames.
Variable Refresh Rate (VRR), G-SYNC & FreeSync
Standard displays refresh on a rigid hardware timer (e.g. every 6.94ms for 144Hz). VRR allows the monitor to wait dynamically for the GPU to finish rendering before triggering scanout, helping reduce tearing and stutter.
AMD's implementation of open-standard VESA Adaptive-Sync over DisplayPort and HDMI. FreeSync Premium and Pro tiers add Low Framerate Compensation (LFC) and certified HDR color calibration.
NVIDIA's proprietary hardware and software synchronization technology. Includes G-SYNC Compatible (Adaptive-Sync validation) and G-SYNC Ultimate (dedicated hardware module with variable overdrive).
Forces the graphics engine to buffer complete frames and hold them until the display's fixed vertical blanking interval. Completely eliminates screen tearing, but can introduce input latency or stutter when FPS drops below refresh rate.
Cable & Port Bandwidth: HDMI vs DisplayPort
Achieving high refresh rates requires sufficient physical transmission bandwidth across your video interface. If a cable, adapter, or GPU port lacks the required throughput for your screen's display resolution and color depth, the system will cap your refresh rate at a lower value.
HDMI 1.4 supports 1080p up to 144Hz in limited configurations, but caps 1440p/4K at 60Hz/30Hz. HDMI 2.0 supports 1080p @ 240Hz, 1440p @ 144Hz, and 4K @ 60Hz.
Up to 48 Gbps uncompressed bandwidth. Supports 4K @ 120Hz/144Hz and 8K @ 60Hz, with support for VRR, Auto Low Latency Mode (ALLM), and eARC.
DP 1.2 supports 1080p @ 240Hz and 1440p @ 165Hz. DP 1.4 adds Display Stream Compression (DSC), supporting 4K @ 144Hz/240Hz with full 10-bit color.
UHBR20 delivers up to 80 Gbps of bandwidth, enabling ultra-high refresh 4K @ 240Hz+ and 8K @ 165Hz setups without perceptible compression artifacts.
Troubleshooting: 144Hz / 240Hz Monitor Stuck at 60Hz
It is common for users who purchase a 120Hz, 144Hz, 165Hz, or 240Hz monitor to inadvertently operate it at 60Hz. Follow this step-by-step diagnostic checklist to verify and unlock your panel's full refresh potential:
Operating systems frequently default new displays to 60Hz. In Windows, open Settings → System → Display → Advanced Display and set your maximum refresh rate. In macOS, check System Settings → Displays.
Ensure your cable is plugged directly into the dedicated graphics card (NVIDIA / AMD) rather than the motherboard's integrated CPU video output port.
Some monitors feature an internal menu setting requiring users to manually enable "DisplayPort 1.4", "HDMI 2.1", or "Overclocking Mode" before high refresh rates appear in the OS.
Passive HDMI-to-DisplayPort adapters and legacy HDMI cables often lack bandwidth for >60Hz signals. Use a certified DisplayPort 1.4 or Ultra High Speed HDMI 2.1 cable.
Laptops on battery power often throttle refresh rates down to 60Hz to save energy. Connect to AC power and check Windows Dynamic Refresh Rate (DRR) settings.
Browsers may throttle background or inactive tabs to conserve system power. Ensure this window remains in the foreground when measuring frame cadence.
What This Tool Can and Cannot Measure
What This Tool Accurately Measures
- Delivered Browser Cadence: Real-time frame presentation rate via high-precision
requestAnimationFrametimestamps. - Frame Time Interval: Exact millisecond spacing between consecutive browser rendering pulses.
- Cadence Jitter & Variance: Deviations and jitter from the expected nominal refresh interval.
- Delayed Frames: Instances where browser rendering took longer than the nominal refresh period.
- Display Stability & P03–P97 Range: Trimmed distribution eliminating extreme outliers to score pacing stability.
- Visual Smoothness: Real-time canvas motion test to visually inspect hitching and micro-stutters.
What Browser Tests Cannot Directly Prove
- Physical Panel Clock: Browsers do not read physical panel circuitry directly like an oscilloscope or optical sensor.
- Pixel Response Time (GtG): Liquid crystal or OLED transition times require high-speed photodiode optical equipment. Also check our Dead Pixel Checker for panel defect inspections.
- End-to-End Input Latency: Total input lag (mouse sensor → PC → display photon scanout) requires dedicated hardware analyzers like our Mouse Checker for input testing.
- Hardware VRR Validation: Browser testing cannot independently verify internal G-SYNC/FreeSync scalar logic.
Frequently Asked Questions
What is monitor refresh rate and what does Hz measure?
Monitor refresh rate, measured in Hertz (Hz), represents the number of times per second a display updates its visual buffer with new image data. For instance, a 60Hz display refreshes 60 times every second (every 16.67ms), whereas a 144Hz panel refreshes 144 times per second (every 6.94ms). Higher refresh rates allow faster visual updates and smoother perceived motion when supplied with sufficient frame rates.
How does this online refresh rate checker test my display?
This tool measures the browser-delivered rendering cadence using the high-resolution requestAnimationFrame browser timing interface. By capturing high-precision DOMHighResTimeStamp values across consecutive display sync intervals, it calculates instantaneous frame durations, rolling averages, timing jitter, and frame pacing stability in real time.
How can I verify if my monitor is actually running at 144Hz or 240Hz?
First, verify that your operating system display settings (Advanced Display Settings in Windows or Displays in macOS) have 144Hz or 240Hz selected. Next, keep this browser tab active and focused and run the Refresh Rate Test. The live measured cadence should stabilize close to the configured refresh rate, allowing for normal browser timing variation.
Why is my 144Hz or 240Hz monitor stuck at 60Hz?
A high-refresh monitor frequently runs at 60Hz because: (1) Windows or macOS defaults to 60Hz until manually configured; (2) the display cable or adapter lacks necessary bandwidth (e.g., older HDMI revisions); (3) the display port on the GPU or laptop is bandwidth-constrained; (4) display drivers need updating; or (5) laptop battery-saving modes have dynamically capped refresh rates.
What is the difference between refresh rate (Hz) and frame rate (FPS)?
Refresh rate (Hz) is the physical or configured frequency at which your monitor refreshes its screen. Frame rate (Frames Per Second or FPS) is the rate at which your graphics card and application render new complete image frames. While FPS dictates how many new frames are generated, refresh rate dictates how many frames the display can physically present per second.
Can FPS exceed my monitor's refresh rate?
Yes, a graphics card can render frames faster than the monitor refreshes (e.g., rendering 240 FPS on a 144Hz display). In uncapped modes without synchronization, this can yield slightly lower input latency at the expense of screen tearing, where multiple partial frames appear across a single display refresh cycle.
What is frame time and how does it relate to Hz?
Frame time is the duration in milliseconds between consecutive frame presentations, calculated mathematically as 1000 / Hz. For example, 60Hz corresponds to 16.67ms, 120Hz to 8.33ms, 144Hz to 6.94ms, 240Hz to 4.17ms, and 360Hz to 2.78ms. Shorter frame times mean visual updates occur more rapidly.
What is frame pacing and why does it affect smoothness?
Frame pacing refers to the consistency and uniformity of frame intervals over time. Even if an application averages 60 or 144 FPS, erratic spacing between frames (such as alternating 5ms and 28ms intervals) creates visible hitching and micro-stutter. Consistent, uniform frame pacing is vital for fluid motion.
What causes micro-stuttering on high refresh displays?
Micro-stuttering occurs when frame delivery intervals fluctuate abruptly due to background CPU/GPU tasks, browser scheduler preemption, memory garbage collection spikes, misconfigured sync modes, or mismatched frame rates and refresh cycles.
What is the difference between dropped frames and delayed frames?
In this timing analyzer, Delayed Frames tracks presentation intervals that took significantly longer than the nominal refresh period (e.g., exceeding 1.5x the baseline frame time), indicating browser compositor hiccups or timing delays. Dropped frames in video playback or game engines generally refer to rendered buffers skipped entirely before display."
What is Variable Refresh Rate (VRR) and how do FreeSync and G-SYNC work?
Variable Refresh Rate (VRR) allows a compatible monitor to synchronize its physical refresh cycle dynamically with the graphics card's instantaneous rendering rate. Technologies like AMD FreeSync and NVIDIA G-SYNC can reduce tearing and help reduce stutter when operating within a compatible VRR range.
Does a higher refresh rate reduce input lag?
A higher refresh rate reduces the display presentation latency portion of input lag by shortening the interval between when a finished frame is delivered and when the panel updates. However, overall end-to-end latency also depends on input polling, game engine processing, render queues, and GPU rendering times.
Does a higher refresh rate reduce motion blur and ghosting?
Higher refresh rates reduce eye-tracking motion blur caused by sample-and-hold display presentation by presenting smaller spatial jumps between frames. However, panel ghosting is determined by pixel response time (the time pixels take to transition colors). A fast refresh rate on a slow-response panel can still display ghosting trails.
What is the difference between refresh rate and pixel response time?
Refresh rate (Hz) describes how frequently the display updates per second, while pixel response time describes how quickly individual pixels transition between shades; actual performance varies by panel, overdrive setting, and measurement method. Both contribute to overall motion clarity.
Is 60Hz good enough for everyday productivity and gaming?
Yes, 60Hz is fully capable for office work, document editing, video playback, and casual gaming. However, higher refresh rates (120Hz–165Hz+) provide noticeably smoother window dragging, text scrolling, and improved clarity in fast-paced competitive games.
Is upgrading from 144Hz to 240Hz worth it?
Upgrading from 144Hz (6.94ms frame time) to 240Hz (4.17ms frame time) saves approximately 2.77ms per frame. While competitive esports players benefit from the increased fluidity and tracking clarity, the perceptual leap is less pronounced than moving from 60Hz (16.67ms) to 144Hz (6.94ms, an 9.73ms improvement).
Why do browser refresh rate tests sometimes differ from Windows or Mac display settings?
Browser tests evaluate delivered rendering cadence via requestAnimationFrame rather than reading panel hardware clocks directly. Browser compositor load, background tab throttling, OS power profiles, or multi-monitor vsync synchronization can cause slight variations from configured OS settings.
Why does the test tab need to stay active and focused during testing?
Browsers may throttle background or inactive tabs, which can significantly affect frame-timing measurements. Keeping the browser window active and in focus ensures that browser-delivered rendering cadence is evaluated without background power-saving throttling.
Can cables like HDMI or DisplayPort limit my monitor's refresh rate?
Yes. Video cables, adapters, and port versions (e.g., HDMI 1.4 vs 2.0 vs 2.1, DisplayPort 1.2 vs 1.4 vs 2.1) have fixed bandwidth ceilings. If a cable cannot support your resolution and color depth at high Hz, the display will drop to a lower supported refresh rate.
Does enabling battery saver on laptops reduce the refresh rate?
Yes, many laptops utilize Dynamic Refresh Rate (DRR) or power-saving profiles that may reduce display refresh rate or system performance when unplugged or when battery saver is engaged.
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