Refresh Rate Tester

Understanding Screen Refresh Rate and What Your Results Tell You

What Is a Screen Refresh Rate?

Your monitor's refresh rate describes how many times per second the output redraws the image — measured in hertz (cycles per second). A 60Hz output redraws 60 times every second; a faster unit redraws 144 times. From a hardware perspective, this is a fixed property of the scanning beam and backlight cycle, set by the specs and the signal your graphics card delivers. It is entirely separate from resolution — a 4K unit can run at 60Hz or at a higher rate depending on the connection standard and graphics driver configuration in use. Use the ppi calculator to compare the pixel density of different monitors before purchasing a replacement display.

Higher output cycle rates translate directly into smoother motion: navigation fluidity, window dragging, pointer tracking, and animation all benefit because more frames are shown per second. It also reduces trailing since each frame is held for a shorter time before the next one replaces it. For some users, particularly those sensitive to strobing, a higher cycle rate also contributes to reduced eye strain — fewer visible strobe cycles and less visual fatigue over extended sessions, which matters for ergonomics and long-term eye health. This improvement in visual quality is one of the primary reasons enthusiasts invest in faster panels.

Hz vs FPS — Refresh Rate vs Frame Rate Explained

One of the most common points of confusion is the relationship between output frequency and frame rate. Refresh rate is a property of the output: it is set in hardware and system output configuration, and it dictates how often the unit physically updates. Frames per second is a property of the graphics card: it measures how quickly the graphics hardware renders and delivers new frames to the output buffer. When these two values are mismatched — for example, when your graphics card renders at 120 fps but your unit is configured to a lower rate — the result is either image tearing (frames split across two cycles) or, if v-sync is active, capped output. Variable refresh rate technology (vrr), including g-sync and freesync and hdmi vrr, solves this by allowing the output to dynamically adapt its timing to match graphics card frame-by-frame, achieving tearing elimination without the response delay penalty of traditional v-sync lock.

In web clients specifically, v-sync means the rendering loop is always synchronised to the active cycle rate via requestAnimationFrame. This is why the fps check this tool performs is an effective proxy for detecting your output's actual refresh rate — the client cannot render faster than the output cycles, so fps equals the rate under a clean, unloaded system.

Common Refresh Rate Values: 24/30 Hz, 60 Hz, 120 Hz, and 240 Hz

Different use cases call for different framerates. Here is a breakdown of the values you are most likely to encounter:

• 24 or 30 Hz — The standard for cinema and television. Films are traditionally shot and exhibited at 24fps; broadcast television uses 30fps (or 25fps in PAL regions). These low rates can introduce judder on outputs running at non-integer multiples of the source rate, which is why units cycling at 120 times per second are useful for footage — they can show 24fps content at an integer-multiple ratio (5×24 = 120) without frame interpolation.
• 60 Hz — The baseline standard for computer outputs and what the majority of productivity users experience. A frame interval of 16.67ms per frame. Sufficient for internet navigation, productivity, and standard footage playback. High-frame-rate content beyond 60fps cannot be shown without a faster unit.
• 120 Hz — A significant step up in fluidity. A unit at this rate runs at 8.33ms frame intervals, making navigation noticeably more fluid. Used in premium units, modern televisions, and increasingly in smartphone outputs (including iPhone ProMotion). Also the minimum for judder-free 24fps cinema playback via integer-multiple ratio.
• 144 Hz / 240 Hz — The enthusiast tiers for pc gaming. 144Hz is today's entry standard for competitive play; the higher tier is the threshold for serious tournament-level players in first-person shooters and fighting games where every millisecond of reduced response delay and sharper motion matters. The perceptual jump from 60Hz to the 144Hz tier is dramatic; from there to the higher tier the improvement follows diminishing returns, though serious tournament competitors still benefit.

Why High Refresh Rate Matters for Gaming and Everyday Use

The case for high refresh rate goes beyond pc gaming experience. In competitive play, a faster output cycle directly reduces the time between a player's input and the moment it appears on-screen — a form of latency reduction that makes actions feel immediate and gives a real edge. For first-person shooters and online titles specifically, the difference between the standard tier and the 144Hz tier is often the difference between seeing and reacting to an opponent before they react to you.

Outside of play, the benefits are equally real. Internet navigation feels sharper because fluidity improves noticeably. Productivity work on a faster output makes window dragging and cursor tracking feel more natural. From an ergonomics standpoint, reduced strobing at higher cycle rates contributes to less eye strain over a long work session — though backlight PWM dimming (testable with a pwm test) is a separate issue. Even system UI motion benefits: interface transitions render more smoothly, making the desktop feel faster and more responsive without any change to underlying system output.

Ensuring Your High Refresh Rate Is Active: Windows, macOS, and GPU Driver Settings

Many users purchase a 144Hz or faster unit only to discover their system is running at a lower rate because the operating system defaulted on first connection. Here is how to verify and correct this:

• Windows: Right-click the desktop → Display Settings → Advanced Display Settings → select the correct refresh rate from the dropdown. Alternatively, Settings → System → Display → Advanced Display. If the target rate does not appear, check your cable — HDMI 1.4 is limited to 1080p at a lower maximum; HDMI 2.0 and DisplayPort are required for higher combinations of resolution and cycle rate. The output configuration may need to be forced via advanced output configuration if the auto-detected rate defaults lower.
• macOS: System Preferences → Displays. Hold the Option key and click the rate selector to reveal all available rates including ProMotion adaptive options. Mac output settings on Apple Silicon machines handle ProMotion automatically, but external units connected via HDMI may default to a lower rate without manual switching in the output section.
• Graphics Driver: Both NVIDIA Control Panel and AMD Software (Radeon Software) provide rate configuration independent of the OS output section, and sometimes expose rates the OS UI does not list. After changing the rate in either utility, perform verification by returning to this tool and checking whether the reading updates accordingly.
• Cable Standard: As noted, the cable connecting your graphics card to your unit must support the target bandwidth. DP 1.2 supports up to 1080p at a high rate; DP 1.4 handles 4K at 120Hz. HDMI 2.0 supports 1080p at a high rate and 4K at 60Hz; HDMI 1.4 caps at lower combinations. Mismatched cables are the most common cause of a unit failing to reach its rated spec despite correct system output configuration.
• Power Saving Mode: On a portable system, an energy-saving profile is a frequent culprit. Battery throttle can cap rendering — and sometimes the entire output pipeline — at a lower rate to reduce power consumption. Plug in your device and switch to high performance mode in your power profile settings before running a high-speed testing session for accurate results. This is especially true on portables whose outputs support adaptive cycling (LTPO), where battery state directly influences the active rate.
• Graphics Acceleration in the Browser: Ensure hardware acceleration is enabled in your web client. Without it, the rendering pipeline may be capped at 60fps regardless of your output's native rate. This is a common reason for a web client measurement showing 60Hz on a faster capable system.

Interpreting Refresh Rate Detection Results and Troubleshooting Common Issues

Worked Example: 144Hz Monitor Showing 60Hz in the Tester

You have purchased a high-rate unit and connected it to your desktop PC, but the refresh rate tester is showing 60Hz. Here is the diagnostic walkthrough:

1. Check output configuration first. Navigate to Settings → System → Display → Advanced Display Settings. Confirm the rate dropdown shows the correct value selected. Many units default to 60Hz on first connection — this is the most common cause.
2. Check your cable. If you connected via HDMI, confirm whether it is HDMI 1.4 or HDMI 2.0. A lower-spec HDMI cable at 1080p may not reliably deliver the target rate. Switch to a DisplayPort cable (DP 1.2 minimum) if available — DisplayPort is the preferred connection for high-speed outputs.
3. Verify graphics driver settings. Open NVIDIA Control Panel or AMD Software and check the rate configuration under Change Resolution or Output settings. The driver-level setting can override or supplement the OS configuration, and sometimes exposes an option that does not appear in the Windows UI.
4. Enable hardware acceleration in your web client. In your client's settings, confirm hardware acceleration is turned on. Without it, the rendering pipeline may be capped at 60fps regardless of what the output is configured to.
5. Rerun the screen refresh rate test. After making changes, reload this page (or press the test again button) and allow a couple of seconds for the reading to stabilise. If it now shows the correct rate with uniform green bars in the frame time chart, your refresh rate configuration is correct.

Worked Example: Mobile User Sees Lower Reading Than Expected

You own a phone with a 90Hz output and run this checker in a handheld client, but the detected refresh rate shows 60Hz. This is a well-known client vs native limitation: handheld clients do not always render at the device's full native rate. The client's rendering loop is subject to the OS's VRR policy, which on many Android devices caps client content at 60fps to reduce energy use unless the user or OS explicitly grants the client access to the full rate. To maximise your result: plug the device in, disable the energy-saving profile, close all open tabs to free resources, and retest. If the client still shows 60Hz on a faster device, this reflects a client cap rather than a hardware problem — native apps on the same device will render at the full rate.

Worked Example: Red Spikes in the Frame Time Chart

Your output is configured at the target rate and the reading is correct, but the real-time chart shows frequent elevated spikes interrupting otherwise stable bars. These anomalies indicate frames that took longer than expected to render — typically exceeding 20ms on a 144Hz system where the expected frame time is 6.94ms. Common causes include:

• Background tasks: Other applications consuming cpu or graphics resources interrupt the client's rendering loop. Close non-essential programs and open tabs before testing.
• JavaScript cleanup cycles: Scripting engines periodically pause execution for garbage collection, causing a single frame to spike. Occasional isolated anomalies are normal and do not meaningfully affect perceived fluidity.
• System load: Antivirus scans, system updates, or other background tasks competing for resources produce clusters of spikes. If spikes are frequent and grouped, check Task Manager for background processes consuming significant CPU or graphics resources.
• Power profile: A portable system running on battery in an energy-saving profile may not sustain consistent frame delivery. Switching to high performance mode and plugging in typically resolves persistent frame time spikes.

Frame stability — measured by the variance score and jitter variance — is the ultimate indicator of output health and system readiness. An output delivering frame synchronisation with low variance and no elevated spikes is performing optimally. Persistent judder or image tearing alongside spikes usually points to a system resource problem rather than an output hardware fault.