How to test your TV

To test a TV, run the built-in self-test from the settings menu first, then open free browser tests on the television itself to check pixels, backlight, colors, motion, sound and internet speed. The whole check takes about ten minutes, needs no downloads and no other device, and tells you whether a fault sits in the TV or somewhere else. Here is the full flow, in the order that saves the most time.

The complete check, step by step

Do the steps in this order. The early ones catch the faults that matter for a return; the later ones tune what you keep. Every test runs in the TV's own browser at tv-test.com, driven by the remote.

See what the TV can actually do. The TV Capability Test reads resolution, HDR support, video and audio codecs and copy protection straight from the TV's browser, in seconds.
Check the panel for faulty pixels. The Dead Pixel Test cycles nine solid colors; a dot that stays black is dead, a dot stuck on one color may still be saved with the Stuck Pixel Fixer. Clean the screen first, dust is the most common false alarm.
Check the backlight in a dark room. The Backlight Bleed Test exposes light leaking at the edges of an LCD. On an OLED, run the OLED Burn-in Test instead to look for ghosted logos.
Check gradients for banding. The Color Banding Test shows where smooth fades turn into stripes.
Check motion. The TV Motion Test reveals blur, 24p judder and the soap opera effect, so you know which motion settings to change.
Check nothing is cut off. The Overscan Test shows in ten seconds whether the TV is cropping the edges of the picture.
Check the sound. The TV Speaker Test confirms both channels work and nothing rattles; the Audio Sync Test shows whether sound runs ahead of or behind the picture.
Check the internet reaching the TV. The TV Speed Test measures the download rate on the television itself and says whether it is enough for 4K, HDR or Full HD.

If a test shows a problem, its page links the guide that walks through the fix. If everything passes, the set is fine and whatever you saw came from the source, the cable or the app.

Does your TV have a built-in test?

The big three brands ship a self-test in the settings. It shows a short reference clip or picture; if the fault appears there too, it is the TV, not the source. The menu paths, from each maker's own support pages:

Samsung: Home > Settings > All Settings > Support > Device Care > Self Diagnosis > Picture Test (a Sound Test sits in the same menu).
LG (webOS 2021 or later): Settings > All Settings > Support > Screen Self-Diagnosis. On recent OLED models the same check also lives under General > OLED Care > Device Self-Care.
Sony (Google TV / Android TV): Press Help on the remote, or open the Help app, then Status & Diagnostics > Picture/Sound test.

Many other brands, and most streaming sticks, have no user-facing picture test at all. That is exactly the hole the browser tests above fill, and they also go further: A built-in test cannot check HDR signalling, codecs, lip sync or internet speed.

When testing matters most

In the first days of owning a new TV, while the return window is open. A bad panel, heavy bleed or a cluster of dead pixels is a return, not a repair.
Before buying a used or ex-display set. Ten minutes with the browser tests in the seller's living room beats any listing photo. The homepage FAQ has a short version of this check.
When something suddenly looks or sounds wrong. Testing separates the TV from the cable, the box and the app, which is most of the diagnosis.

The numbers worth knowing

Internet speed: 4K streaming needs about 25 Mbit/s per stream; Full HD is comfortable from about 5 Mbit/s. Measure on the TV itself, not at the router.
Data use: Roughly 0.7 GB per hour in SD, 3 GB in Full HD and about 7 GB in 4K on most services; YouTube 4K HDR can reach 13 GB.
Faulty pixels and warranty: Manufacturers follow a tolerance standard (ISO 9241-307), and a single dead pixel is usually below the return threshold. A cluster, or a dead pixel dead-centre, has a stronger claim.
Screen size: A good TV size is roughly two-thirds to four-fifths of your seat distance; the TV Size Calculator does the arithmetic both ways.
Honest limit: TV browsers are capped near 60 frames per second, so a browser can show how a TV treats motion but cannot measure a panel's true refresh rate. The tests here say what they cannot measure instead of guessing.

Questions people ask

How do I test my TV for problems?

Run the TV's built-in picture self-test from the settings menu if it has one, then open tv-test.com in the TV's browser and work through the tests: Capability, dead pixels, backlight bleed or burn-in, color banding, motion, overscan, speakers, audio sync and internet speed. The full pass takes about ten minutes and needs no downloads.

Does my TV have a built-in self-test?

Samsung, LG and Sony ship one: Samsung under Support > Device Care > Self Diagnosis, LG under Support > Screen Self-Diagnosis, Sony under Help > Status & Diagnostics. Many other brands and most streaming sticks have none, in which case browser tests are the only way to check the panel without extra hardware.

How do I test a new TV before the return window closes?

In the first days, run the dead pixel fields, the backlight bleed test in a dark room, and the capability test to confirm the set really does the 4K and HDR it was sold on. Photograph any fault against a solid color field as evidence. A defective panel is a return, not something to live with.

Can I test my TV without installing an app?

Yes. Everything here runs in the browser the TV already has: Open tv-test.com on the television, and the site switches to a large layout you can drive with the remote's arrow keys. Nothing is installed and no account is needed.

Start with the TV Capability Test, or jump straight to the full list of tests. If a result sends you hunting for a fix, the guides cover the common faults one by one.