What causes a glitchy screen and how to fix it

A glitchy screen usually means one of three things: a loose cable, outdated or corrupted graphics drivers, or a display setting that has shifted. Start by checking the physical connection between your monitor and computer — unplug the cable from both ends, wait ten seconds, and plug it back in firmly. If that does not work, restart your computer in Safe Mode, which loads only essential drivers and can reveal whether a third-party program is causing the problem. If the glitches stop in Safe Mode, a driver update or a conflicting process is the culprit.

For laptops, the issue is often a driver problem rather than a cable, since the screen is built in. The same Safe Mode restart applies. On Windows, you can also check Device Manager to see whether your graphics driver shows a warning symbol or needs updating. On Mac, restart and hold Command + S to boot into Single-User Mode, which serves the same diagnostic purpose.

Key Takeaways

  • Reseat your monitor cable by unplugging it from both the monitor and computer, waiting ten seconds, and plugging it back in firmly.
  • Restart your computer in Safe Mode to determine whether a driver or third-party program is causing the glitches rather than a hardware fault.
  • Update your graphics driver through Device Manager on Windows or System Preferences on Mac if Safe Mode clears the problem.
  • Adjust your refresh rate in display settings if you see flickering, as a mismatch between your monitor and computer settings can cause visible distortion.
  • If glitches persist after driver updates and cable checks, the monitor itself may be failing and may need replacement.

Check the cable connection first

The fastest fix is often the simplest. Unplug the video cable — whether it is HDMI, DisplayPort, DVI, or VGA — from the back of your monitor. Look at both the monitor end and the computer end for bent pins, corrosion, or debris. If the connector looks damaged, you may need a replacement cable, which costs between $10 and $30 depending on the type.

Plug the cable back in and make sure it clicks or seats fully. A cable that is not fully inserted will cause flickering, lines, or color distortion. If you have a spare monitor cable of the same type, swap it in to rule out a faulty cable. For laptops, this step does not explore unless you are using an external monitor.

Restart in Safe Mode to isolate the problem

On Windows 10 or 11: Hold Shift and click the power button, then select Restart. When the blue menu appears, choose Troubleshoot, then Advanced Options, then Startup Settings. Press 4 or F4 to boot into Safe Mode. If the screen glitches disappear, a driver or program installed after your last restart is the cause.

On Mac: Restart your computer and hold the Shift key when ready after you hear the startup sound. Release it when you see the login window. This boots into Safe Mode. If glitches stop, restart normally and proceed to update your graphics driver.

Safe Mode loads only the drivers your operating system needs to run. If your screen is stable there, the problem is not a hardware failure — it is a software conflict. Write down what you were doing or what you installed before the glitches started, because that is likely the source.

Update your graphics driver

On Windows: Right-click the Start button and open Device Manager. Expand Display adapters, right-click your graphics card (usually Intel, NVIDIA, or AMD), and select Update driver. Choose Search automatically for updated driver software. Windows will read and install the latest version from the manufacturer. Restart your computer when prompted.

If Windows cannot find an update, visit the manufacturer's website directly. NVIDIA, AMD, and Intel all have driver read pages where you can enter your graphics card model and read the latest version manually. This method often finds newer drivers than Windows Update does.

On Mac: Click the Apple menu, select System Settings (or System Preferences on older versions), then General, then Software Update. Mac handles graphics driver updates as part of the operating system, so there is no separate step. Install any available updates and restart.

Adjust your refresh rate and resolution

A mismatch between your monitor's native refresh rate and your computer's output can cause flickering or visible scan lines. Right-click your desktop on Windows and select Display settings. Scroll down to Advanced display settings, then scroll again to Refresh rate. Your monitor's native refresh rate is usually 60 Hz, but some gaming monitors run at 75 Hz, 144 Hz, or higher. Set this to match your monitor's specification, which is printed on the back or in the manual.

While you are in Display settings, check your resolution. It should match your monitor's native resolution — usually 1920 × 1080 for a standard monitor. If it is set lower, Windows is stretching the image, which can cause distortion. Select the highest resolution available and click explore.

On Mac, click the Apple menu, select System Settings, then Displays. Choose the resolution labeled "Default for display" — this is your monitor's native setting. If you have an external monitor, the same principle applies: use its native resolution and refresh rate.

Disable hardware acceleration if glitches appear only in certain programs

If your screen glitches only when you use a web browser, video player, or specific process, the problem may be hardware acceleration — a feature that offloads graphics processing to your graphics card. Sometimes this feature conflicts with your driver or monitor.

In most web browsers, you can disable hardware acceleration in Settings. In Chrome, go to Settings, then Advanced, then System, and toggle off Use hardware acceleration. In Firefox, go to Preferences, then General, scroll to Performance, and uncheck Use recommended performance settings, then uncheck Accelerated graphics. Restart the browser and test.

If glitches stop, your graphics driver or card may not support that process's acceleration method. You can leave acceleration off, or you can try updating your driver again — sometimes a newer version fixes acceleration conflicts.

Test with an external monitor if you have a laptop

If you own a laptop and have access to an external monitor, connect it to your laptop using an HDMI or USB-C cable. If the external monitor displays without glitches, your laptop's built-in screen is failing and will likely need replacement by a technician. If the external monitor glitches too, the problem is your graphics driver or a software conflict, not the screen hardware.

This test takes five minutes and can save you from replacing a screen when the real issue is a driver. Most laptop screens cost $150 to $400 to replace, so it is worth confirming the diagnosis first.

When to replace your monitor or seek repair

If you have reseated the cable, updated your driver, adjusted your refresh rate, and tested in Safe Mode, and glitches persist, your monitor may be failing. Monitors typically last 5 to 10 years depending on use and heat exposure. Signs of monitor failure include persistent lines, dead pixels that do not change, or flickering that happens even in Safe Mode.

A replacement monitor costs between $100 and $300 for a standard 24-inch model, depending on resolution and features. If your monitor is under warranty (usually one to three years), contact the manufacturer with your proof of purchase — they may replace it for free or at a reduced cost. If it is out of warranty and the repair cost exceeds half the price of a new monitor, replacement is usually the better choice.

Frequently Asked Questions

Why does my screen only glitch when I move my mouse?

This usually means your cable is loose or partially damaged. The movement of your mouse generates electrical noise, which interferes with a weak signal. Reseat your monitor cable firmly at both ends. If glitches continue, try a different cable of the same type.

Can dust or heat cause a glitchy screen?

Dust can block ventilation on a monitor, causing it to overheat and malfunction. If your monitor feels hot to the touch or sits in direct sunlight, move it to a cooler location and use compressed air to blow dust out of the vents. Heat rarely causes glitches in graphics drivers, but it can shorten monitor lifespan.

What if my screen glitches only at startup?

Startup glitches often mean your graphics driver is loading and has not fully initialized yet. This is usually harmless and stops within a few seconds. If glitches persist after your desktop fully loads, follow the driver update steps above. If they stop after a few seconds every time, no action is needed.

Does overclocking my graphics card cause screen glitches?

Yes. If you have overclocked your GPU for gaming or performance, dial back the clock speed or voltage. Overclocking pushes your graphics card beyond its tested limits, and instability shows up as screen artifacts, flickering, or color distortion. Return your card to stock settings and test.

Should I try uninstalling and reinstalling my graphics driver?

Only if updating does not work. On Windows, open Device Manager, right-click your graphics card, and select Uninstall device. Check the box to delete the driver software, then restart. Windows will reinstall the default driver. Then follow the update steps to install the latest version from the manufacturer. This takes longer than a straightforward update but can fix corruption in the driver files.