Screen Tearing Test

How this test works

Track the aligned markers while changing speed and direction. A tear may appear as a horizontal break in alignment.

1. Prepare the display using the checklist below.
2. Select Start test and allow fullscreen mode if your browser asks.
3. Use the arrow keys, on-screen controls, or click the pattern to move through the test.
4. Exit the runner and save a local observation if useful.

Before you begin

• Use the display's native refresh rate
• Keep the browser in the foreground
• Test V-Sync or variable refresh settings separately

What to look for

• Horizontal breaks through moving bars
• Misaligned sections of the same marker
• Repeated stutter or cadence changes

Look for a split in one moving marker

The runner moves vertical markers so you can watch whether one line appears displaced above and below a horizontal break. That visual split is different from a uniformly blurred edge or a faint trail following the marker. Change speed and direction while keeping the page in the foreground at your intended display mode. If motion simply advances unevenly without a split, describe it as stutter or cadence instability rather than tearing. The exact visible effect can be brief, so observe several cycles before drawing a conclusion.

A browser often presents frames through synchronized composition. That can conceal tearing even on a system where a full-screen game or another application tears. Absence of a line on this page therefore does not certify tear-free operation elsewhere. Conversely, a strange break in a camera video may come from rolling shutter rather than the display. Use your eyes first and compare a real application where the problem occurs before treating the browser pattern as evidence about the entire graphics pipeline.

Separate tearing from frame pacing and ghosting

Tearing is a spatial mismatch within a displayed frame. Frame pacing is about when complete frames arrive, so uneven pacing may feel like a hitch without any horizontal seam. Ghosting is a trail or duplicate attached to a moving object, and pixel response can contribute to that appearance. The refresh cadence page estimates browser callback timing, while the ghosting page focuses on trails. Use these focused checks to describe the motion problem precisely; one result should not be used as a substitute for another.

V-Sync, variable refresh rate, frame caps, operating-system compositing, and the application’s own settings can all change the visible outcome. Compare one configuration at a time and keep a record of the display mode and app. A variable-refresh feature may reduce tearing within its supported range but does not make every combination of hardware and frame rate behave identically. This browser page cannot read the panel scan directly or confirm that a named adaptive-sync feature is active.

Interpret a negative result cautiously

If the marker remains aligned, report that no split was visible in this browser under these conditions. Do not conclude that the monitor can never tear. If a split is visible, repeat at the same speed, then compare your application’s sync settings and frame cap. Make sure the effect is not a nearby window, reflection, or camera artifact. The most useful record includes the display refresh mode, browser, graphics setup, speed, direction, and whether the issue also appears in real content.

A browser-generated tearing pattern is a qualitative visual aid. It does not measure input lag, response time, scanout duration, or frame delivery from a game engine. Any quantitative claim about those properties requires a separate validated method. If your primary complaint is smeared motion, try ghosting or response patterns instead. If your complaint is a repeated hitch, investigate frame timing and application load. Choosing the right phenomenon prevents unnecessary hardware conclusions based on a single synthetic animation.

Frequently asked questions