TVs

TV picture looks pixelated or blocky

Blocky or pixelated video usually comes from a weak signal, whether that's a streaming connection, antenna signal, or cable box feed, rather than the TV itself.

Difficulty
Easy
Time
10–20 minutes
DIY cost
$0–$15
Pro cost
$60–$120

Symptoms

  • Video breaks into square blocks briefly
  • Picture looks fine then suddenly pixelates during motion
  • Problem is worse on one channel or app than others
  • Pixelation increases during storms or bad weather

Likely causes

  • CommonWeak or unstable internet connection for streamingStreaming apps compress video more aggressively when bandwidth drops, causing visible blocks.
  • CommonWeak antenna or cable signalOver-the-air and some cable signals degrade with weather, distance, or a loose connector.
  • PossibleDamaged or loose coaxial/HDMI cableA frayed or poorly connected cable can introduce visible compression artifacts.
  • PossibleSource device or app streaming bugA specific app or device can have a bug that causes blocky video even on a good connection.

What to do

  1. Check if pixelation happens on one specific app or channel, or across everything, to narrow down the source.
  2. Run an internet speed test near the TV if the issue is on a streaming app.
  3. Restart your router and the streaming device or smart TV.
  4. Check antenna or cable connections for looseness, and reposition an antenna if reception is weak.
  5. Try a wired Ethernet connection instead of Wi-Fi for the streaming device if possible.
  6. Lower the streaming quality setting manually in the app if your connection can't sustain HD or 4K.
  7. Contact your cable or satellite provider if pixelation happens consistently on their signal, since it may indicate a line issue.

Tools and parts

Coaxial cableSearch: “RG6 coaxial cable”

When to call a pro

If pixelation happens on every source including live antenna channels with a strong signal, a technician can check the tuner hardware.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.