Screen Tearing Test

Screen tearing is a visual distortion where a display presents portions of multiple frames in a single screen draw. It appears as a horizontal split or seam where the top and bottom sections of the image are slightly shifted out of alignment.

Tearing looks like a sharp, horizontal hairline fracture across a moving scene. As you turn or as objects sweep horizontally, the graphics above the line appear slightly ahead of or behind the graphics below the line.

Tearing happens when the graphics card feeds a new completed frame to the display buffer while the monitor is actively scanning lines onto the screen. Without vertical synchronization (VSync), the scanout switches mid-frame to the newer image.

Yes. If your GPU renders at a higher frame rate than your monitor can display (e.g. 250 FPS on a 144Hz monitor) and VSync is off, multiple buffer swaps will occur during a single scan cycle, creating multiple horizontal tear lines.

Yes. Vertical Synchronization locks buffer swaps to the monitor's vertical blanking interval (VBLANK). Because the monitor only receives new frames when it finishes scanning the entire panel, tearing is completely eliminated.

At 144Hz, frames are replaced every 6.94ms instead of 16.67ms (60Hz). The physical displacement between consecutive frames is smaller, making tear lines narrower and less conspicuous, but tearing is not mathematically eliminated without synchronization.

No. 240Hz drastically narrows the offset between frames (4.17ms), making tears harder to see during fast gameplay, but tearing can still occur unless G-Sync, FreeSync, or VSync is engaged.

VSync (Vertical Synchronization) is a graphics pipeline protocol that delays buffer swapping until the display concludes its current refresh pass, ensuring that only whole, unbroken frames are presented to the viewer.

FreeSync is AMD's adaptive sync technology that dynamically alters the monitor's physical refresh rate to match the instantaneous frame output of the GPU, eliminating both tearing and VSync-induced stutter.

G-SYNC is NVIDIA's hardware-synchronized variable refresh rate (VRR) technology that aligns the display's panel cycle with GPU frame completion, providing tear-free visuals without traditional VSync input lag.

Frame pacing describes how consistently consecutive frames are delivered in time. Even if an application averages 60 FPS, erratic frame intervals (e.g. alternating 8ms and 24ms) cause perceptible judder and micro-stutter.

Modern displays scan pixel rows horizontally from top to bottom (raster scan). When the frame buffer swaps during this sweep, the remainder of the vertical frame is drawn from the newer image, forming a horizontal line of discontinuity.

No. Web browsers run inside a sandboxed graphics abstraction (Direct3D, Metal, or OpenGL) and cannot monitor the physical electron/optical scanout of the display. This tool provides deterministic motion patterns so you can inspect tearing with your own eyes.

No. Browser JavaScript cannot access GPU driver control panel settings (e.g. NVIDIA Control Panel or AMD Software). 'Browser VSync' in this tool refers to requestAnimationFrame presentation scheduling.

In windowed mode, the desktop window manager (DWM in Windows or Quartz in macOS) typically composites all windows with mandatory desktop VSync. Exclusive fullscreen mode allows direct swapchain access, where tearing can appear if VSync is disabled in the driver.

Tearing is not caused by low frame rates; it is caused by lack of phase synchronization. In fact, frame rates substantially higher than your refresh rate cause multiple tear lines across a single frame.

No. This tool simply animates standard 2D vector shapes and canvas pixels within standard web browser APIs. It cannot cause any physical damage to your monitor.