What Is an FPS Tester?
An FPS tester measures how often a visual sequence is updated during a defined observation window. On this page, the sequence is driven by the browser’s animation scheduler. The tester records the timestamp supplied for every animation frame, subtracts consecutive timestamps, and treats the difference as a frame interval. Those intervals support a browser FPS estimate and a much richer view of delivery consistency than a single counter can provide.
This distinction matters. A browser FPS test describes this page, in this browser, on the currently active display. It does not read the render pipeline of a game running elsewhere, inspect GPU driver counters, or predict the frame rate of a particular title. For native game FPS, use an in-game counter or a trusted operating-system capture tool. Use FPS Tester when the question concerns browser cadence, frame timing, display scheduling, or whether browser animation is behaving consistently.
FPS comparison animation
Compare 15, 30, 60, and 144 FPS motion at the same 240 px/s speed. Every lane covers the same distance over time, but lower rates hold each position longer and move in larger steps. The controlled animation separates update frequency from travel speed so the comparison remains fair.
How to Get Started
Close unnecessary heavy tabs, keep this page visible, and place the window on the display you intend to observe. Set the Stress Level slider to the browser workload you want to inspect. The test performs a short warm-up before recording results because startup scheduling and canvas initialization can otherwise distort the beginning of a sample.
- Set the Stress Level before starting, or adjust it while the test runs to watch the browser cadence respond.
- Select Start FPS Test, keep the tab visible, and follow the one-point-per-second FPS chart as the animated workload runs.
- Select Stop Test when you have enough data, then compare average FPS with frame time, 1% low, jitter, and timing spikes or copy the results.
What This FPS Tester Measures
Current FPS is a short-window reciprocal of recent frame intervals, while average FPS is calculated as 1000 divided by the mean interval in milliseconds. Minimum and maximum values show the range of equivalent rates seen in valid samples. Median frame time identifies the typical delivery interval and is less sensitive to an isolated long frame than the mean. The 1% low summarizes the slowest one percent of intervals when at least 100 valid samples exist.
Frame-time jitter is the median absolute distance from the median interval. The stability score maps that relative jitter to a bounded 0–100 consistency scale; it intentionally does not reward 144 FPS merely for being faster than a perfectly even 60 FPS. A timing spike is an interval above both 1.5 times the current median baseline and a four-millisecond absolute margin. It is evidence of an irregular interval, not proof of a dropped frame.
Understanding FPS, Frame Time, and 1% Low
FPS and frame time express the same cadence from opposite directions. At a perfectly even 60 FPS, each frame has about 16.67 milliseconds. At 120 FPS the budget is about 8.33 milliseconds, and at 144 FPS it is roughly 6.94 milliseconds. Because the relationship is reciprocal, averaging a list of instantaneous FPS values can be misleading. This FPS tester therefore averages intervals first and converts that result to FPS.
Averages can hide brief disruptions. Two sessions may both report 60 FPS on average, yet one can contain several 35-millisecond intervals that feel like hitches. A lower 1% low, wider interval spread, higher jitter, or repeated spike count makes that behavior visible. Read these metrics together instead of searching for one universal “good” number; the useful baseline is a repeat under comparable conditions on the same device and display.
When an Online FPS Test Is Useful
An online FPS test is useful after changing a browser setting, moving a window between monitors, connecting a laptop charger, disabling battery saver, or investigating an animation that looks uneven. Developers can use it as a quick environmental check before profiling a particular web application. Display owners can compare the observed cadence with the selected operating-system refresh setting. Gamers can learn how frame time and lows behave before applying the same concepts to native-game telemetry.
For a useful comparison, run the FPS checker more than once and change only one condition between runs. A background download, video call, thermal limit, browser extension, or operating-system update can affect scheduling. A single short test should not be treated as a permanent rating for a computer. Repeated samples make it easier to distinguish a persistent cadence pattern from one accidental interruption.
Why Browser FPS Is Not In-Game FPS
The browser receives callbacks when it is appropriate to prepare another visual update, commonly near the active display cadence. A game has its own engine, scene complexity, graphics API, resolution, quality settings, upscaling, frame limiter, and driver path. None of that native telemetry is exposed to this web page. The FPS tester cannot tell you exactly how CS2, Fortnite, Valorant, Roblox, or any other separate application will perform.
Browser FPS can also appear capped near the monitor refresh rate because browsers normally synchronize animation work with presentation. That is expected and is not a GPU ceiling. If this tester stays near 60 on a display expected to run at 144 Hz, check the operating-system display setting, active monitor, cable path, power saving, and browser window location. Then use the dedicated refresh-rate test for a robust cadence estimate.
Factors, Users, and Practical Limits
Browser version, operating system, active monitor, tab visibility, window occlusion, power mode, thermal state, system load, extensions, and variable-refresh behavior can all alter the result. The page stops an active test if it becomes hidden so that a background-tab gap is not counted as a normal frame. Starting again performs a new warm-up. Very short runs may not contain enough samples for 1% low, and 0.1% low requires a much larger set.
The FPS tester suits people checking web animation, display cadence, frame-delivery consistency, or the meaning of performance metrics. It is not a certified diagnostic and cannot prove that a GPU or monitor is faulty. If results are unexpectedly uneven, repeat in a current browser with extensions minimized and other displays disconnected only if convenient. Persistent problems across controlled repeats are a reason to investigate settings and system telemetry, not a diagnosis by themselves.