Why You Probably Can't Tell 144Hz From 240Hz Apart

2026-08-08

Quick Answer

Each step up in refresh rate delivers a smaller proportional reduction in frame time than the last, so perceptual gains shrink even as the Hz numbers keep climbing. 60 to 144Hz cuts frame time by more than half; 144 to 240Hz cuts it by well under half again, which is why the second jump is so much harder to notice.

The Hz number hides what actually matters

Refresh rate marketing trains people to think in a straight line: bigger Hz number, better experience, no exceptions. But what your eyes actually respond to is frame time, the gap between one frame appearing and the next, and that gap does not shrink in a straight line as Hz climbs.

At 60Hz, each frame stays on screen for 16.7 milliseconds. At 144Hz, that drops to 6.9 milliseconds, a reduction of almost 10ms. At 240Hz, it drops further to 4.2ms, a reduction of only about 2.7ms from 144Hz. The Hz numbers went up by roughly the same amount both times, 84Hz and then 96Hz, but the actual frame time improvement was more than three times bigger on the first jump than the second.

This is a diminishing returns curve, not a broken product. Every doubling of Hz only manages to halve the frame time again, so each successive jump buys you less real reduction in the gap your eyes are trying to perceive.

Why marketing numbers make this hard to judge honestly

Almost nobody experiences a monitor upgrade blind. You know you paid for 240Hz, the box says 240Hz, the OSD confirms 240Hz, and that expectation alone is enough to make most people report a smoother experience regardless of whether their eyes could isolate the difference from labeling alone. This is not a character flaw, it is just how expectation biases perception in essentially every domain, from wine tasting to audio equipment.

The only honest way around that is a genuine blind comparison, where you do not know which clip is which until after you commit to an answer.

What a browser can and cannot simulate

A monitor physically cannot draw faster than its own real refresh rate, so no test can show you what a rate above your panel's maximum would look like. What a browser test can do reasonably well is simulate rates at or below your panel's real maximum, by holding an object's on-screen position steady across several real refreshes to reproduce the same judder that content genuinely running at that lower rate would show.

That is the mechanism behind ScreenLab's FPS Blind Test: it measures your panel's actual refresh rate first, then only ever compares simulated rates within that ceiling, so a 165Hz monitor is tested against realistic options like 60, 90, 120, and 165, never against a number it could not physically display anyway.

What the results usually look like

Most people score close to perfect on pairs with a large proportional gap, like 60 versus 144. Scores drop noticeably on pairs near the top of a fast panel's range, like 144 versus 240, where the frame time gap has shrunk to just a couple of milliseconds. That pattern lines up with the frame time math above rather than with any specific brand or panel type, which is why it shows up consistently across different displays and different people.

A cluster of "looked the same" answers on the tightest pairs is not a failure. It is the expected result once the underlying frame time difference gets small enough, and it is genuinely useful information if you are deciding whether your next upgrade should chase a bigger Hz number or spend that money somewhere else, like panel type, response time, or HDR brightness.

Frequently Asked Questions

Why does 60 to 144Hz feel like a bigger jump than 144 to 240Hz?

What you actually perceive is the change in frame time, not the change in Hz. Going from 60Hz to 144Hz cuts frame time from 16.7ms to 6.9ms, a drop of nearly 10ms. Going from 144Hz to 240Hz only cuts it from 6.9ms to 4.2ms, a drop of under 3ms, even though the Hz gap looks similar on paper.

Is there a point where more Hz stops mattering at all?

For pure motion clarity, most research on human motion perception puts meaningfully diminishing returns somewhere around 240 to 360Hz for the average viewer, though competitive players training specifically on fast target tracking can sometimes push that higher. Content also matters: a fast-panning competitive shooter shows differences a slow-paced strategy game never will.

Does this mean buying a 240Hz monitor is a waste of money?

Not necessarily. A faster panel can still mean lower input lag, and if you already have the frame rate and GPU headroom to feed it consistently, there is no downside beyond cost. The point is that a blind test is a more honest way to decide it matters to you than assuming a bigger Hz number automatically means a proportionally bigger visual upgrade.

How can I test whether I can actually tell the difference myself?

Use something that removes the label, since knowing which rate you are looking at is itself enough to bias the answer. ScreenLab's FPS Blind Test plays two clips at simulated frame rates capped to your own panel's measured refresh rate and asks you to guess which was smoother without telling you which is which.

Why do the two clips in a blind test sometimes look identical?

When the proportional difference between two rates is small, like 165Hz versus 240Hz, the frame time gap between them can shrink to just a couple of milliseconds, which is genuinely difficult for most people to distinguish in a moving image. Scoring that pair as a tie is a completely normal and expected outcome, not a failed test.