Monitor Refresh Rate Test
Estimate your monitor's actual refresh rate using requestAnimationFrame. See your FPS and detected Hz in real time.
Keep this tab in the foreground for accurate results. The measurement improves with more samples.
How Does the Monitor Refresh Rate Test Work?
- The tool uses requestAnimationFrame to measure the time between screen updates.
- It collects hundreds of frame timing samples to calculate your average FPS.
- The median frame rate is matched to the nearest standard refresh rate (60, 75, 120, 144, etc.).
- Outlier samples are trimmed to improve accuracy.
Refresh Rate vs Frame Rate: What's the Difference?
Refresh rate (measured in Hertz, Hz) is how many times per second your monitor redraws the screen. A 144Hz monitor refreshes 144 times per second. Frame rate (measured in frames per second, FPS) is how many unique images your graphics card produces per second. These are independent — a 144Hz monitor displaying a game running at 60 FPS will repeat some frames, while a game running at 200 FPS on a 144Hz monitor wastes the extra frames unless VSync is disabled.
For the smoothest experience, your frame rate should match or exceed your refresh rate. When they are mismatched and no synchronization technology is active, you get screen tearing — visible horizontal lines where two different frames overlap. This is why knowing your actual refresh rate matters: if your monitor is set to 60Hz when it supports 144Hz, you are missing out on smoothness even when your GPU can deliver the frames.
Adaptive Sync: G-Sync, FreeSync, and VRR
Adaptive sync technologies dynamically match your monitor's refresh rate to your GPU's frame output, eliminating both tearing and the stuttering caused by traditional VSync. NVIDIA's G-Sync requires a dedicated hardware module in the monitor, while AMD's FreeSync uses the open VESA Adaptive-Sync standard and costs nothing extra to implement. Since 2019, NVIDIA GPUs also support FreeSync monitors under the "G-Sync Compatible" label. Console gamers benefit from VRR (Variable Refresh Rate) on HDMI 2.1, which works on the same principle.
These technologies only work within a specific range — for example, a FreeSync monitor might support adaptive sync between 48Hz and 144Hz. Below the floor, the monitor falls back to standard behavior. LFC (Low Framerate Compensation) addresses this by doubling frames when FPS drops below the adaptive range, keeping the experience smooth even during demanding scenes.
Common Refresh Rate Issues and How to Fix Them
The most common issue is running at a lower refresh rate than your monitor supports. After connecting a new high-refresh monitor, both Windows and macOS may default to 60Hz. On Windows, go to Settings > Display > Advanced display settings and select the correct refresh rate. On macOS, hold the Option key while clicking "Scaled" in Display settings to reveal refresh rate options.
Cable limitations can silently cap your refresh rate. HDMI 1.4 supports 1080p at 120Hz but only 4K at 30Hz. HDMI 2.0 handles 4K at 60Hz. For 4K at 120Hz or higher, you need HDMI 2.1 or DisplayPort 1.4 with DSC. If this test shows a lower refresh rate than expected, check that your cable and port support the resolution-refresh combination you want. A $5 cable rated for a lower standard will bottleneck a $500 monitor.
Frequently Asked Questions
- Why does it show 60Hz when my monitor is 144Hz?
- Your browser or operating system may be limiting the frame rate. Make sure hardware acceleration is enabled in your browser, VSync matches your monitor rate, and you're not in battery saver mode.
- How accurate is this test?
- Browser-based refresh rate detection is an estimate. requestAnimationFrame is subject to browser throttling, background tab limitations, and system load. For exact specifications, check your monitor's manual or display settings.
- What is a good refresh rate?
- 60Hz is standard for most monitors. 120Hz and 144Hz are popular for gaming. 240Hz and above are used by competitive gamers. Higher refresh rates provide smoother motion and lower input lag.