Refresh Rate Test - Check Your Screen's Actual Hz Online
Find out what refresh rate your screen is actually running at - not just what the monitor claims to support. This free Refresh Rate Test measures your display's real Hz, tracks frame intervals, detects skipped frames, and checks timing stability in about five seconds. It runs in your browser and compares the result with the closest standard refresh rate.
Keep this window in front and don't scroll while it runs.
—Hz
Ready when you are
Each bar is one frame interval. A locked display makes a flat line; a fluctuating one makes noise.
All measurements
- Measured rate
- —Hz
- Frame interval
- —ms
- Variance
- —ms
- Frames counted
- —
- Skipped frames
- —
- Shortest interval
- —ms
- Longest interval
- —ms
- Closest standard
- —Hz
- Resolution
- —
- Pixel ratio
- —×
- Colour depth
- —bit
- Signal needed
- —Gbps
Displays tested this session
Drag this window onto your other screen and run the test again. Each display is listed separately so you can compare them.
| Display | Resolution | Measured | Skipped |
|---|
How the Refresh Rate Test Works
1. Choose Your Refresh Rate
Select your expected refresh rate from 60 Hz to 360 Hz, or choose "I don't know my monitor's rating" if you're unsure.
2. Run the Test
Click Start Test and keep this browser tab in front for about five seconds while the tool measures refresh cycles and frame intervals.
3. Review Your Results
See your measured Hz, frame interval, timing variance, skipped frames, and the closest standard refresh rate. Everything runs locally in your browser.
Understanding Test Result
The All Measurements section explains how your display performs beyond the final Hz number. Each metric reveals a different part of your screen's refresh timing, signal quality, and display configuration.
- Measured Rate: The actual refresh rate detected during the test.
- Frame Interval: The time between refreshes. For example, 8.333 ms matches a 120 Hz display.
- Variance: How much the frame interval changes. Lower variance means steadier motion.
- Frames Counted: The total refresh cycles measured during the five-second test.
- Skipped Frames: Missed refresh cycles that can cause stutter or uneven motion.
- Shortest and Longest Interval: The fastest and slowest refresh times recorded, helping identify timing spikes.
- Closest Standard: The nearest common refresh rate, such as 60 Hz, 120 Hz, 144 Hz, or 240 Hz.
- Resolution, Pixel Ratio, and Color Depth: Your active display settings that affect image quality and scaling.
- Signal Needed: The minimum bandwidth your HDMI or DisplayPort connection requires to support the current resolution and refresh rate.
Together, these measurements help you verify both your display settings and cable compatibility.
Why Your Monitor May Run at the Wrong Refresh Rate
Your monitor may run below its expected refresh rate even when the panel supports a higher Hz. The most common causes are incorrect display settings, an older HDMI or DisplayPort cable, outdated graphics drivers, or power-saving mode limiting the signal.
A 144 Hz monitor can also fall back to 60 Hz if the wrong cable version or display mode is selected. If your measured rate is lower than expected, check your operating system's display settings, update your graphics driver, and make sure your cable has enough bandwidth for your current resolution and refresh rate.
Can Your Cable Carry That Refresh Rate?
Your display cable can limit your refresh rate, even when your monitor and graphics card support higher settings. Every HDMI and DisplayPort version has a maximum bandwidth, and that limit changes with resolution, color depth, and Hz. If the connection cannot carry enough data, the display often falls back to a lower refresh rate.
The table below shows what each cable version can realistically handle.
| Cable Version | Maximum Bandwidth | Best For | Limitation |
|---|---|---|---|
| HDMI 1.4 | 8.2 Gbps | 1080p at 144 Hz | Cannot run 1440p at 144 Hz. |
| HDMI 2.0 | 14.4 Gbps | 1440p at 144 Hz or 4K at 60 Hz | Limited for higher 4K refresh rates. |
| HDMI 2.1 | 42.6 Gbps | 4K at 144 Hz | Requires a certified HDMI 2.1 cable. |
| DisplayPort 1.2 | 17.3 Gbps | 1440p at 165 Hz or 4K at 60 Hz | Not ideal for 240 Hz displays. |
| DisplayPort 1.4 | 25.9 Gbps | 1440p at 240 Hz or 4K at 120 Hz | Higher settings may rely on Display Stream Compression (DSC). |
| DisplayPort 2.1 | 77.4 Gbps | 4K at 240 Hz and beyond | Support depends on compatible hardware. |
Quick Takeaways
- Choose HDMI 2.1 for high-refresh 4K gaming.
- Use DisplayPort 1.4 for 1440p at 240 Hz.
- DisplayPort 2.1 offers the highest bandwidth for future-ready displays.
- An older cable can force your monitor to run at a lower refresh rate, even if the monitor itself supports higher Hz.
FAQs
What is a refresh rate?
Refresh rate is the number of times your screen updates the image every second, measured in Hertz (Hz). A higher refresh rate usually makes scrolling, gaming, and animations look smoother because the display refreshes more often.
Is the refresh rate the same as FPS?
No. Refresh rate measures how often your monitor updates the screen, while FPS (Frames Per Second) measures how many frames your device or browser renders each second. The smoothest experience happens when both stay close to the same value.
Why does my 144 Hz monitor only show 60 Hz?
A 144 Hz monitor may show 60 Hz because of display settings, an older HDMI cable, outdated graphics drivers, or mirrored display mode. Switching to the correct refresh rate in your operating system and using a compatible cable usually fixes the issue.
What is a good refresh rate for gaming?
60 Hz is good for everyday gaming, 120 Hz and 144 Hz provide smoother motion for competitive play, and 240 Hz benefits fast-paced esports games. The right choice depends on your monitor, graphics card, and the games you play.
Does HDMI support 240 Hz?
Yes, but it depends on the HDMI version and your display resolution. HDMI 2.1 can support 240 Hz at supported resolutions, while older HDMI versions have lower bandwidth limits.
Is DisplayPort better than HDMI for high refresh rates?
Display Port is often the better choice for high refresh rate monitors because newer versions support higher bandwidth. For example, DisplayPort 1.4 can handle 1440p at 240 Hz, while DisplayPort 2.1 supports even higher refresh rates and resolutions.
Does this Refresh Rate Test work on Mac and mobile?
Yes. The tool works on Windows, Mac, Android, and iPhone through modern browsers like Chrome, Safari, Edge, and Firefox. Results may vary slightly depending on your device, browser, and display capabilities.
Why does my measured refresh rate differ slightly from the selected value?
A small difference is normal because browsers measure refresh timing in real time rather than reading the monitor's advertised specification. Minor variations in frame intervals and system timing do not usually indicate a display problem.