A TV run starts at the edges of the picture, then goes through gray uniformity, black and blooming, the ramps, black level, color and sharpness, with the TV preset picked so your shared card says it was a TV.
Where to open it matters. A TV’s built-in browser usually renders web pages at a lower resolution than the panel and upscales them, so in it the edge and 1-pixel sharpness patterns show the browser’s scaling, not the panel. The gray fields, black, ramps and colors are fine there. For the edge and sharpness tests, connect a laptop or PC over HDMI, set it to the TV’s native resolution, open this page and press Start full-screen test; Space moves on, or use the buttons under the pattern.
1. Edges: is the whole picture shown?
The first pattern draws a white border on the outermost pixels, with guides at 2.5% and 5% in from the edge. Over HDMI, many TVs crop the edges of the picture (overscan) unless you change the picture size. If the white border or the corner marks are cut off:
- Samsung: on recent models, Settings > All Settings > Picture > Expert Settings > Picture Size Settings > Fit to Screen (per Samsung’s US support; it depends on the picture size and input).
- LG: All Settings > Picture > Aspect Ratio (> User Selection on recent webOS) > Just Scan; LG calls it the ideal setting for a PC, game console or Blu-ray player.
- Other brands: look for a picture size or aspect ratio setting that shows the full picture.
2. Uniformity, black and blooming
On the gray fields, look for darker edges, vertical bands and blotches, the “dirty screen effect” RTINGS describes as most visible in large uniform colors such as sports and panning shots. On black, an LCD TV with local dimming may brighten zones around the bar at the bottom of the screen: that halo is blooming. Hide the bar (tap the pattern, or H) to see the black on its own.
3. Ramps, black level and color
The ramps show banding in skies and dark scenes, the numbered squares show whether shadows and highlights are crushed, and the swatches show whether colors and skin tones look natural. Judge color in the picture mode you will actually watch in, and compare a couple of modes if skin tones look off.
4. Sharpness
Single-pixel lines and small text show whether the TV shows the picture pixel for pixel. Blur, shimmer or a wavy pattern in the rings means the picture is being scaled: check the picture size setting from step 1, and that the source sends the TV’s native resolution.
For an OLED TV, follow up with the OLED test for true black and burn-in. For dead pixels, the dead pixel test works in a TV browser too.