The Basic Difference Between FPS and Hz
Frames per second is an application output rate. A game engine, video stream, or browser animation may create or schedule a certain number of distinct frames each second. Hertz is cycles per second; for a display, refresh rate describes how often the selected mode can update the screen. FPS belongs to content production, while Hz belongs to display timing.
The numbers often appear together because frames must eventually be presented during display refresh opportunities. They do not need to match exactly, and matching labels do not guarantee even presentation. Frame pacing, synchronization, queueing, variable refresh range, and actual performance determine how well the two timelines align.
60 FPS on a 60 Hz Display
In the ideal case, each 60 FPS frame is ready for one 60 Hz refresh, producing a new complete frame about every 16.67 ms. Real systems are less exact. If one frame takes longer, it can miss an opportunity and remain visible for another refresh. If unsynchronized presentation changes the buffer mid-scan, a tear may become visible.
V-Sync can wait for refresh boundaries and avoid mid-scan tearing, but missed timing may create repeated frames or queueing depending on the application. A frame cap can reduce unnecessary work, while consistent pacing determines whether “60 FPS” actually arrives evenly. The average label alone does not describe those details.
60 FPS on a 144 Hz Display
A 144 Hz display offers a refresh about every 6.94 ms, while evenly paced 60 FPS content produces a frame every 16.67 ms. Some refreshes must therefore show the same content, and the ratio does not divide evenly. Presentation can alternate how long individual source frames remain visible unless synchronization or interpolation manages the relationship.
The higher-refresh display may still offer lower scan timing and more frequent opportunities for interface updates, but it does not transform sixty unique source frames into 144 real rendered frames. Motion smoothness remains limited by content rate and pacing. Television motion interpolation can synthesize frames, which is a separate process and may add artifacts or latency.
144 FPS on a 60 Hz Display
An application can produce 144 FPS even when a fixed display refreshes at 60 Hz. The screen cannot show 144 complete distinct scans each second. Without synchronization, newer frames may replace older ones during a scan, creating spatial tearing. With synchronization, some produced work may never become a distinct presentation, and frame queues or caps affect latency behavior.
Rendering above refresh can still reduce the age of the newest available frame in some unsynchronized game configurations, which is why competitive settings are not a simple “FPS must equal Hz” rule. The tradeoff depends on the engine and presentation mode. Browser tools cannot configure or directly measure that native path.
V-Sync and Variable Refresh Rate
Vertical synchronization coordinates presentation with fixed refresh boundaries to reduce tearing. Depending on buffering and implementation, it can add waiting or produce cadence changes when performance falls below target. A limiter set appropriately near a stable target can interact with that queue. Exact tuning should follow current application, driver, and display guidance.
Variable refresh rate allows a compatible display to vary refresh timing so it can present a new frame when ready within a supported range. FreeSync, G-SYNC, and standards-based Adaptive-Sync are implementations or ecosystems around that concept. VRR does not eliminate every stutter, work outside its range without additional handling, or guarantee that every application uses it.
Tearing, Stutter, and Motion Blur
Tearing is a spatial discontinuity from different frame states appearing across a scan. Stutter is uneven motion caused by irregular timing or repeated content. Motion blur is loss of clarity during movement and can arise from sample-and-hold perception, pixel transitions, source blur, or processing. A rate mismatch can contribute to presentation issues, but the symptoms are not synonyms.
Use the screen tearing test for a controlled visual pattern, frame pacing for interval rhythm, and motion blur test for pursuit clarity. Each browser tool observes or displays a limited part of the chain. None can automatically certify a monitor or diagnose a native game from outside that application.
The Browser Measurement Boundary
Browser animation callbacks often track the active display cadence, which makes them useful for estimating refresh rate. The estimate remains indirect: the page does not read EDID or watch every scan. Windows spanning monitors, browser policy, dynamic refresh, remote desktops, battery saver, and system load can all alter callback timing. A result near 60 may reflect the currently selected mode rather than a hardware maximum.
Use the refresh-rate test with the window fully on one display, then compare it with operating-system settings. Use an in-game counter for native FPS. Understanding FPS vs Hz begins with keeping production and presentation as separate signals and ends with selecting a measurement tool that actually sees the layer in question.