Use this browser-based display test to compare frame-callback timing with a selected refresh-rate setting. It uses requestAnimationFrame; it does not directly measure the monitor panel or diagnose a cable or GPU fault. Results can vary with browser scheduling, device workload, and power settings on laptops, desktops, and phones.
What is a Screen Hz Test and How Does It Work?
A monitor refresh rate is the number of times per second a display can update an image, expressed in Hertz (Hz), where 1 Hz equals one update per second. This browser-based screen Hz test estimates callback timing; it does not directly measure a physical panel.
The test uses the high-resolution timer and requestAnimationFrame timestamps to calculate intervals between browser callbacks. These callbacks are scheduled around browser rendering, not exposed as a direct hardware sensor reading, and may be throttled or paused, especially in background tabs. By keeping a rolling buffer of recent callbacks, the tool reports live estimates and min/max interval values. These describe sampled browser timing, not the panel's precise physical refresh rate.
The frame consistency tracker summarizes the standard deviation of recent callback intervals. We label this value "interval variation": it describes browser-side timing in this session, not a standardized panel-jitter score or a diagnosis of stutter and display lag.
Why Should You Check Your Monitor Refresh Rate?
A high-performance 144Hz or 240Hz monitor can still be set to a lower refresh-rate mode in the operating system. Available modes depend on the display, connection, and setup, so check the selected setting directly. This page samples browser callbacks; comparing the estimate with the system setting cannot identify whether a cable, GPU, or display setting caused a difference.
Common reasons to check your monitor's refresh-rate setting include:
- Verify Hardware Settings: Check that your display is set to a supported refresh-rate mode in your operating system; compare this page's browser estimate, which does not verify the panel mode directly.
- Check Cable and Connection Limits: Supported resolutions and refresh rates depend on the display, port, adapter, and cable. This test cannot identify cable bandwidth or signal errors, so check your display settings and device documentation.
- Optimize Gaming Smoothness: Higher refresh rates can present visual updates more frequently, but perceived motion and latency also depend on the application, frame rate, synchronization, and display settings.
- Improve Office Scrolling: Higher refresh rates can make scrolling appear smoother. This test does not evaluate eye strain, flicker, or other health effects.
- Check Browser Timing: Browser settings and device workload can affect callback timing. This test cannot determine whether hardware acceleration is enabled or whether a device is capped at 60Hz.
Hertz Breakdown: 60Hz vs. 120Hz vs. 144Hz vs. 240Hz vs. 360Hz
Different display refresh rate classes offer vastly different user experiences. Understanding these differences can help you make informed decisions when buying new monitors or adjusting your setup. Run our refresh rate analyzer to see where your current display sits in this performance hierarchy.
| Refresh Rate | Frame Time Target | Primary Use Case | Smoothness Level |
|---|---|---|---|
| 60 Hz | 16.67 ms | Standard office work, web browsing, movie viewing | Standard (Baseline) |
| 75 Hz | 13.33 ms | Budget office setups, entry-level casual gaming | Moderate Improvement |
| 120 Hz | 8.33 ms | Modern smartphones, next-gen gaming consoles (PS5/Xbox Series X) | Very Smooth |
| 144 Hz | 6.94 ms | Standard PC gaming setup, fast action games | Ultra Smooth |
| 240 Hz | 4.17 ms | Competitive eSports setups, professional gaming, enthusiast PCs | Elite Smoothness |
| 360Hz - 500Hz | 2.00 - 2.77 ms | Hardcore competitive eSports, pro leagues, extreme latency reduction | Maximum Performance |
As you can see from the comparison table, moving from a 60Hz display to a 144Hz or 240Hz mode shortens the interval between refresh updates. A 60Hz mode has an interval of about 16.67 milliseconds, whereas 240Hz is about 4.17 milliseconds. These intervals describe display refresh timing; they do not guarantee a particular reaction-time improvement or competitive advantage.
Refresh Rate (Hz) vs. Frame Rate (FPS) Explained
A common point of confusion among desktop users is the difference between refresh rate (expressed as screen Hz) and frame rate (expressed as FPS). Although they are mathematically similar, they occur at different stages of the graphics rendering pipeline:
Frame Rate (FPS) represents how quickly your computer's graphics processing unit (GPU) can calculate and render new frames of video game code or animation. It is determined by the processing power of your processor (CPU), graphics card (GPU), and the complexity of the game scenes you are viewing. If your system is powerful, your GPU might output 200 FPS in a specific eSports title.
Refresh Rate (Hz) represents how many times your monitor can physically redraw the screen to display those rendered frames. It is a physical hardware limit built directly into your monitor panel by the manufacturer.
If a graphics card renders 200 frames per second while a display refreshes at 60Hz, the display still has at most 60 refresh opportunities per second; synchronization settings affect how rendered frames are presented. Conversely, a 240Hz display does not make a game render at 240 FPS. This screen Hz test reports browser callback timing; it does not measure game FPS or independently verify the monitor's hardware mode.
How to Change Your Monitor's Refresh Rate
If you suspect a refresh-rate limit, check the selected mode in your operating system settings. The browser estimate cannot identify the cause; the steps below show where to review available modes on Windows and macOS:
Adjusting Refresh Rate on Windows 10 & Windows 11
- Open your system configuration settings by pressing the Windows Key + I on your keyboard, or click the Start Menu and select the gear icon.
- Click on the System category, and then choose the Display menu option in the sidebar.
- If you have multiple monitors connected, select the graphic representation of the specific monitor you wish to adjust at the top of the page.
- Scroll down the display page and click on Advanced display settings.
- Under the display information block, find the setting labeled Choose a refresh rate (or click 'Display adapter properties for Display' and go to the 'Monitor' tab).
- Open the dropdown list and select a mode supported by your monitor and connection (for example, 120Hz, 144Hz, 240Hz, or 360Hz if available).
- Click Apply. Your screen may black out for a second and prompt you with 'Keep these changes?'. Select Keep changes.
- Return to this monitor tester webpage and refresh it to compare browser callback timing with the selected operating-system mode. The tool does not independently verify the display's hardware refresh rate.
Adjusting Refresh Rate on macOS (MacBook Pro & Studio Displays)
- Click on the Apple Logo Menu in the top-left corner of your desktop screen and select System Settings (or 'System Preferences' on older macOS versions).
- In the system settings sidebar, scroll down and click on Displays.
- If you have an external monitor connected, click on its thumbnail icon to select it.
- Locate the option labeled Refresh Rate. This setting is typically positioned below the resolution options.
- Review the available refresh-rate options and choose a mode supported by the selected display. ProMotion availability and dynamic behavior depend on the Mac model and settings.
- Close Settings and refresh this page to compare browser callback timing with the selected mode. This does not independently verify the panel's physical refresh rate.
Troubleshooting: Why is My Monitor Capped at 60Hz?
If a monitor appears capped at 60Hz, check its selected operating-system mode and the display, port, adapter, and cable specifications. A different browser estimate cannot identify the cause; the checks below are general troubleshooting steps, not diagnoses produced by this tool.
1. Outdated or Undersized Display Cables
Available refresh rates depend on the connection bandwidth as well as the display and graphics hardware. A cable or adapter may limit some resolution and refresh-rate combinations, but the exact limits depend on the port versions and display configuration. Check the specifications for your devices and connection:
- DisplayPort: Check the supported resolution and refresh-rate combinations for the specific DisplayPort version, GPU, monitor, and any adapter.
- HDMI: Check the supported resolution and refresh-rate combinations for the specific HDMI version, GPU, monitor, and any adapter.
2. Missing or Corrupted GPU Drivers
A missing or incompatible graphics driver can affect which display modes are available, but the browser test cannot diagnose a driver issue or confirm a 60Hz limit. Check Windows display settings and the documentation from your GPU manufacturer (NVIDIA, AMD, or Intel) for your specific hardware.
3. Browser Hardware Acceleration is Disabled
Browser acceleration settings may affect rendering, but this test cannot read that setting or attribute a callback rate to it. Browser and device scheduling can vary; check the browser's own settings and retest with this page in the foreground.
To review hardware acceleration in Google Chrome: Click the three dots in the top-right corner → select Settings → click System in the sidebar → review Use graphics acceleration when available → click Relaunch if you change it. This screen Hz test cannot confirm which rendering device the browser used.
4. Multi-Monitor Refresh-Rate Settings
In a multi-monitor setup, refresh-rate modes are selected separately for each display. Check the setting for the display you want to use and consult current operating-system and GPU documentation if available modes differ from the specifications. This browser tool cannot diagnose a multi-monitor issue.