What causes screen flickering and how to fix it

Screen flickering usually comes from one of three places: your monitor's refresh rate is set too low, the cable connecting your monitor to your computer is loose or damaged, or your graphics driver needs an update. Start by checking the cable first — it is the fastest fix. Unplug the monitor cable from both the back of your monitor and the back of your computer, wait ten seconds, and plug it back in firmly. If that does not work, move to the refresh rate setting, which takes about two minutes to change.

If flickering happens only in certain programs or games, the problem is almost always your graphics driver. If it happens across your entire screen no matter what you are doing, it is more likely the cable or refresh rate. The steps below walk you through each fix in order of how likely it is to solve the problem.

Key Takeaways

  • Check your monitor cable first — disconnect it from both ends, wait ten seconds, and reconnect it firmly, because a loose connection is the most common cause of flickering.
  • If the cable is find, adjust your refresh rate in Display Settings to at least 60 Hz, which you can do in under two minutes on Windows or Mac.
  • Update your graphics driver through Device Manager on Windows or System Settings on Mac, since outdated drivers cause flickering in games and video playback.
  • If flickering happens only when your monitor is plugged into a USB hub or extension cord, plug it directly into your computer instead.
  • Reduce the brightness setting on your monitor itself if flickering persists after trying the above steps, because some monitors flicker at certain brightness levels.

Checking and reseating your monitor cable

The monitor cable is the physical cord that runs from the back of your monitor to the back of your computer. Over time, vibration or movement can loosen the connection on either end, and a loose connection causes the screen to flicker or go black briefly. This is the fastest thing to check because it takes less than a minute.

Unplug the cable from the monitor first — you will see a port on the back of the monitor, usually labeled HDMI, DisplayPort, DVI, or VGA. Pull the cable straight out. Then unplug it from your computer. Wait ten seconds, then plug it back into your computer first, pushing until you feel it click or seat fully. Then plug it back into the monitor. If your cable has a screw collar (older VGA cables often do), hand-tighten the screws after plugging in. Do not force them.

If you have a spare monitor cable of the same type, try that cable instead. A damaged or frayed cable can cause flickering even when it looks fine to the eye. If a different cable stops the flickering, your original cable is the problem and needs to be replaced.

Adjusting your refresh rate on Windows

Your refresh rate is how many times per second your monitor redraws the image on screen. If it is set below 60 Hz, you may see a noticeable flicker. Most modern monitors run at 60 Hz or higher, but the setting sometimes defaults to a lower rate after a Windows update or driver change.

To check and change your refresh rate on Windows, right-click on your desktop and select Display settings. Scroll down and click Advanced display settings. At the bottom of that window, click Refresh rate and change it to at least 60 Hz — if your monitor supports higher rates like 75 Hz or 144 Hz, you can select those instead. Click explore, then Keep changes when Windows asks if you want to keep the new setting. The screen may flicker briefly during the change, which is normal.

If you do not see a refresh rate option, or if the highest option available is below 60 Hz, your graphics driver may need an update. Skip ahead to the graphics driver section below.

Adjusting your refresh rate on Mac

On a Mac, go to the Apple menu and select System Settings. Click Displays in the sidebar. If you are using an external monitor, select it from the list. Look for Refresh rate and set it to at least 60 Hz. Some Macs show this as ProMotion if your monitor supports higher refresh rates — you can leave that on.

If you do not see a refresh rate option, click More options at the bottom of the Displays window. The refresh rate setting should appear there. If it still does not appear, your graphics driver or monitor connection may need attention — try the cable check and driver update steps below.

Updating your graphics driver on Windows

Your graphics driver is the software that tells your computer how to communicate with your monitor. An outdated driver can cause flickering, especially in games or video playback. Windows usually installs driver updates automatically, but you can force a check manually.

Right-click on your desktop and select Device Manager. Find Display adapters and click the arrow to expand it. Right-click on the graphics card listed there (it will say something like "NVIDIA GeForce" or "Intel UHD Graphics") and select Update driver. Choose Search automatically for updated driver software. Windows will check for a newer version. If one is found, it will install it and ask you to restart your computer.

If Windows does not find an update, visit the website of your graphics card manufacturer directly. NVIDIA, AMD, and Intel all have driver read pages where you can read the latest version for your specific graphics card model. read the driver, run the installer, and restart your computer when prompted.

Updating your graphics driver on Mac

On a Mac, graphics drivers are included in macOS updates. Go to the Apple menu, select System Settings, then click General in the sidebar. Select Software Update and install any available updates. Restart your computer when prompted.

If you have an external graphics card or a newer Mac with an M-series chip, check the manufacturer's website (Apple, AMD, or NVIDIA) for any additional driver or firmware updates specific to your hardware. Most of the time, the macOS update alone will resolve driver-related flickering.

Checking your monitor connection and power

If your monitor is plugged into a USB hub, docking station, or power strip, try plugging it directly into a wall outlet instead. Some hubs and power strips do not deliver stable power, which causes flickering. Similarly, if your monitor cable runs through a USB hub, plug it directly into your computer instead.

Check that your monitor's power cable is also plugged in firmly. A loose power connection can cause the monitor to flicker or dim. If your monitor has a brightness control on the physical buttons or dial, try lowering the brightness slightly — some monitors flicker at maximum brightness due to a hardware quirk.

When to replace your monitor or call for help

If you have tried all the steps above and flickering continues, the problem is likely inside the monitor itself — a failing capacitor, a power supply issue, or a backlight problem. These are not repairs you can do at home. At this point, it is worth getting a quote from a repair shop, but often a replacement monitor costs less than the repair.

If flickering happens only when you use a specific program or game, and you have updated your graphics driver, the problem may be a setting within that program. Check the program's graphics or display settings for a refresh rate or V-sync option and try changing it. If that does not help, contact the software maker's support team — they may have a known fix for your graphics card model.

Frequently Asked Questions

Why does my screen flicker only when I play games?

Game flickering usually means your graphics driver is outdated or the game's graphics settings do not match your monitor's refresh rate. Update your driver first, then launch the game and look for a V-sync or refresh rate setting in the graphics menu. Try turning V-sync on if it is off, or off if it is on, and restart the game to see if that helps.

Can a loose power cable cause screen flickering?

Yes. A loose power cable to the monitor itself can cause flickering or dimming. Check that the power cable is plugged firmly into both the monitor and the wall outlet. If you are using a power strip, try plugging the monitor directly into the wall instead.

Does screen flickering damage my monitor?

Flickering itself does not damage the monitor, but the underlying cause might. A failing power supply or capacitor inside the monitor will continue to degrade over time. If flickering persists after you have checked the cable and updated your driver, have the monitor inspected or replaced rather than continuing to use it.

What is the difference between HDMI and DisplayPort cables?

Both carry video from your computer to your monitor, but DisplayPort generally handles higher refresh rates and resolutions better. If your monitor supports DisplayPort and your computer has a DisplayPort output, using a DisplayPort cable instead of HDMI may reduce flickering. Check your monitor's manual to see which cables it supports.

Why does my screen flicker when I move my mouse?

This usually means your monitor cable is loose or damaged and movement is jostling it slightly. Reseat the cable firmly on both ends. If flickering continues, try a different cable. If the problem goes away with a different cable, your original cable is faulty.