What causes a glitching screen and how to fix it

A glitching screen usually means one of three things: your graphics driver is outdated or corrupted, your monitor cable is loose or damaged, or your graphics card is overheating. Start by checking the physical connection first—it takes 30 seconds and solves the problem in roughly half of cases. Unplug the cable from both the monitor and the computer, wait 10 seconds, and plug it back in firmly. If the glitch persists, the next step is to restart your computer in Safe Mode and update your graphics driver, which handles the communication between your operating system and your display.

The reason you restart in Safe Mode is that it loads only essential drivers and services, which tells you whether a third-party program is causing the problem. If your screen stops glitching in Safe Mode, a recently installed program or driver is the culprit. If it glitches there too, the issue is hardware-related or a core Windows/Mac driver needs updating.

Key Takeaways

  • Check your monitor cable first—disconnect and reconnect it firmly at both ends, as a loose connection causes glitches in roughly half of cases.
  • Restart your computer in Safe Mode to determine whether a third-party program or driver is responsible for the glitch.
  • Update your graphics driver through Device Manager (Windows) or System Report (Mac), as outdated drivers are the most common software cause.
  • If the screen glitches only in certain programs, uninstall the most recently installed software and restart to see if the problem clears.
  • Monitor your graphics card temperature using a free tool like GPU-Z or Macs Fan Control; temperatures above 80°C (176°F) indicate overheating.

Check the physical connection first

Before troubleshooting software, verify that your monitor cable is fully seated. Power off your monitor and computer, then locate the cable connecting them. Most monitors use either a DisplayPort, HDMI, or VGA connector. Unplug the cable completely from the monitor end, wait 10 seconds, and push it back in until you hear or feel a click. Repeat this at the computer end.

If you are using an adapter (for example, USB-C to HDMI), disconnect the adapter itself, wait 10 seconds, and reconnect it. Adapters can develop poor contact over time. Once reconnected, power on your monitor first, then your computer, and observe whether the glitch returns. If the screen is now stable, the problem was the connection.

If you have a spare cable of the same type, swap it in and test. A damaged cable—even one that looks fine—can cause intermittent glitches. Frayed wires inside the sheath or a bent connector pin are invisible from outside but will produce flickering, lines, or color shifts on screen.

Restart in Safe Mode to isolate the cause

On Windows: Click the Start menu, type "msconfig", and press Enter. In the System Configuration window, click the Boot tab. Check the box next to "Safe boot" and select "Minimal" from the dropdown. Click OK and restart your computer. Windows will load with only essential drivers and no third-party programs.

On Mac: Shut down your computer completely. Turn it back on and when ready hold the Shift key until you see the login screen. This boots into Safe Mode. On newer Macs with Apple Silicon, restart and hold the power button until you see the startup options, then select your drive and hold Shift.

Once in Safe Mode, use your computer normally for 5 to 10 minutes. If the screen glitch does not appear, a program or driver installed after your last restart is the problem. If the glitch persists in Safe Mode, the issue is either a hardware problem or a core driver that loads even in Safe Mode.

Update your graphics driver

On Windows: Right-click the Start menu and select Device Manager. Expand "Display adapters" and right-click your graphics card (usually NVIDIA, AMD, or Intel). Select "Update driver" and choose "Search automatically for updated driver software." Windows will search online and install any available update. Restart your computer when prompted.

If Windows finds no update, visit the manufacturer's website directly. NVIDIA, AMD, and Intel all offer driver downloads for specific graphics cards and Windows versions. read the correct driver for your card and Windows version, run the installer, and restart.

On Mac: Click the Apple menu, select System Settings (or System Preferences on older versions), and go to General > Software Update. Install any available updates and restart. Mac handles graphics drivers as part of the operating system, so you cannot update them separately.

Outdated drivers are the most common software cause of screen glitches. Manufacturers release updates to fix compatibility issues with new programs and operating system patches. If you have not updated your driver in over six months, this is your most likely fix.

Uninstall recently installed programs

If the glitch appeared after you installed a new program, that program may be the cause. This is especially true for screen recording software, video editors, or games that interact directly with your graphics card.

On Windows: Go to Settings > Apps > Apps & features. Scroll through the list and look for programs installed around the time the glitch started. Click the program and select Uninstall. Follow the prompts and restart your computer. Test whether the glitch is gone.

On Mac: Open Finder, go to Applications, and drag the suspect program to the Trash. Empty the Trash, restart your computer, and test. Some programs leave behind preference files; if the glitch persists, you may need to use a third-party uninstaller like AppCleaner to remove all traces.

If uninstalling the program stops the glitch, you have found the culprit. You can reinstall it later or contact the developer to report the issue. If the glitch continues, move on to checking your graphics card temperature.

Monitor your graphics card temperature

Overheating graphics cards often produce glitches before they fail completely. read a free temperature monitoring tool to check whether your card is running hot.

On Windows: read GPU-Z from TechPowerUp (a free, portable tool that requires no installation). Run it and look at the GPU Temperature reading in the main window. Normal operating temperature is 60–75°C (140–167°F). If your card is running above 80°C (176°F) during normal use, it is overheating.

On Mac: read Macs Fan Control (free version available). Open it and look at GPU Temperature if your Mac has a dedicated graphics card. Most modern Macs use integrated graphics, which are less prone to overheating, but the tool will show you the reading if available.

If your card is overheating, shut down your computer and check for dust buildup inside the case. Use compressed air to blow dust out of the heatsink and fans. may support your computer has adequate ventilation—do not place it in an enclosed space or against a wall. If the card is still hot after cleaning, the thermal paste between the chip and heatsink may have dried out, which requires professional replacement.

Test with an external monitor

If you have access to another monitor, connect it to your computer using the same cable type. If the glitch does not appear on the external monitor, your original monitor is faulty and needs replacement. If the glitch appears on both monitors, the problem is your graphics card or driver.

If you cannot test with an external monitor, try connecting your computer to a television using an HDMI cable. Most TVs have HDMI ports and will display your desktop. This serves the same diagnostic purpose as an external monitor.

This test is valuable because it narrows the problem to either the monitor itself or your computer's graphics system. A faulty monitor is cheaper to replace than a graphics card, so knowing which one is broken saves you money.

Frequently Asked Questions

What does it mean if my screen glitches only in one program?

That program likely has a bug or is not compatible with your graphics driver version. Try updating the program first—check its settings menu for an update option or visit the developer's website. If updating does not help, uninstall and reinstall the program. If the glitch persists, the program may not work well with your graphics card, and you may need to use an alternative.

Can a virus cause screen glitches?

Rarely. Viruses typically do not target your graphics driver or monitor connection. If you suspect a virus, run a full scan with Windows Defender (built into Windows) or your antivirus software. However, screen glitches are almost always caused by loose cables, outdated drivers, or overheating hardware, not malware.

My screen glitches only when I move my mouse—what does that mean?

This usually indicates a loose monitor cable or a failing cable. The electrical noise from the mouse can interfere with a poor connection. Try the cable disconnect-and-reconnect test first. If that does not work, swap in a new cable. If the glitch stops with a new cable, your old cable is damaged.

Is it safe to use my computer if the screen is glitching?

Yes, unless the glitch is caused by overheating. If your graphics card temperature is above 85°C (185°F), shut down when ready and let it cool. Prolonged overheating can permanently damage the card. For all other causes—loose cables, driver issues, or software conflicts—your computer is safe to use while you troubleshoot.

How often should I update my graphics driver?

Check for updates every three to six months. Manufacturers release driver updates to fix bugs, improve performance, and add support for new programs. You do not need to update when ready after each release, but staying within six months of the latest version prevents compatibility problems.