Why your MacBook screen is flickering and how to stop it

Wondering why is my MacBook screen is flickering, I’ve fought this on my own MacBook running macOS Tahoe. Here’s the plan I use that actually works, to diagnose it, fix it, and keep your system smooth moving forward, so let's get started.

Diagnose the problem: Is it software or hardware?

Do the fastest check first. Plug in an external display and mirror. If the external stays steady while the built-in flickers, suspect software settings or the internal display path, such as the flex cable. If both screens flicker, think system-wide software or a hardware controller issue.

Then note the pattern, only in one app like Chrome, Zoom, or Photoshop, or right after sleep. That points to settings, extensions, or GPU handoff. A flicker that changes with the lid angle usually means cable or panel.

Before you dive deeper, clear the easy. I run Smart Care from CleanMyMac to remove app caches and temporary files. Sometimes corrupt cache data triggers false hardware warnings; here's how:

1. Open CleanMyMac — get your free trial here (you can test it for 7 days).

2. Select Smart Care > Scan.

3. Run tasks and items.

Now rule out obvious faults with Apple Diagnostics; here's how:

1. Shut your Mac down.

• Apple silicon: press and hold the power button until Options appears, then press Command - D to start diagnostics.

• Intel: restart and hold D. Let the test finish and note any reference codes.

My decision tree is simple

• External OK + no diagnostic errors = treat it as software in the next sections.

• When both screens flicker, or diagnostics flag an issue = keep reading but be ready for a hardware path later.

Why is my MacBook Pro screen flickering? The quickest fixes first

When the flicker is new or intermittent, I try these two-minute moves before anything advanced.

1. Restart the Mac

Head to your main menu and hit Restart. This often solves a surprising share of cases by clearing stuck display and UI processes.

2. Turn off True Tone

1. System Settings > Displays.

2. Toggle True Tone off. If the shimmer stops, leave it off for now.

3. Switch out of Dark Mode

1. System Settings > Appearance.

2. Choose Light. Some apps glitch only with dark themes.

4. Disable automatic brightness

1. System Settings > Displays.

2. Turn Auto-brightness off, set a fixed level, and test. Sudden ambient light changes can look like flicker.

5. Close all apps and test

Simply quit everything, then open a single app like Notes or Safari. If the flicker disappears, reopen apps one by one to find the trigger.

6. Clean startup noise if it began after a new install

Sometimes a fresh app adds a helper that fights the GPU at login. Use the Performance feature from CleanMyMac to manage login items and background processes; here's how:

1. Open CleanMyMac > Performance > Scan > View All Tasks.

2. Review Login Items and Background items. Disable anything you do not need, then restart and retest. This is just quicker than hunting through multiple panes in System Settings.

System updates & maintenance

So, a big part of keeping your Mac running smoothly is by staying up-to-date, which alone can solve issues before they happen, like Why is my MacBook Air screen flickering.

1. Update macOS

Staying current fixes a lot of flicker cases; here's a reminder of how:

1. System Settings > General > Software Update.

2. Update your apps

1. Open the App Store > Updates.

2. Next update non-Store apps from their built-in updaters (Adobe, Zoom, browsers): click the app name in the menu bar and choose Check for Updates.

3. Clear stale caches

Run CleanMyMac, or a similar maintenance tool of choice, to clear caches and temporary files.

4. Restart after updates

A full reboot resets display services and finishes post-update cleanup.

Advanced display settings and color profiles

Use these only if the quick fixes and updates above didn’t help.

1. Clean up color profiles or presets

• System Settings > Displays > Preset.
• Pick a non-HDR preset (for example, Apple Display (P3-500 nits) or a standard sRGB/Display P3). Changing the preset swaps the color profile and tone mapping.

2. Adjust refresh rate

• System Settings > Displays.
• Set Refresh Rate to 60 Hz instead of ProMotion/Automatic.

3. Custom resolutions (older Macs only)

Tools like SwitchResX can force stable timings on legacy external monitors. Use sparingly: pick a standard 60 Hz mode first.

4. PRAM/NVRAM reset (Intel only)

Shut down > power on and hold Option - Command - P - R for around the 20-second mark, until the second startup chime (or second Apple logo).

Apple silicon has no manual NVRAM reset; a full shutdown and cold boot are sufficient.

Security & performance checks

If you skipped Apple Diagnostics earlier, run it now to rule out obvious hardware issues (steps in Diagnose the Problem: Is It Software or Hardware? section)

1. Look for malware or unwanted tools

I run CleanMyMac > Protection > Scan and let it check for adware, miners, and shady launch agents. It is a quick sanity check when a flicker appears with no clear trigger.

2. Watch Activity Monitor while the flicker happens

Open Activity Monitor > CPU and leave it visible. If the screen jitters when a single process jumps to the top, you have your suspect. Quit it and retest.

3. Safe mode test

Restart in safe mode and use the Mac for a few minutes. If the flicker stops, a third-party extension or login item is involved.

4. Audit startup apps

Remove extra launch items so background helpers do not pile on. System Settings > General > Login Items, then disable anything you do not need.

When it's hardware: Cable, LCD, or inverter issues

If flicker changes with lid angle, briefly stops when you press the bezel, or shows on both the built-in and an external display, you are likely looking at hardware. Common culprits are the LVDS flex cable, the LCD assembly, or the logic board path.

Ballpark costs: cable 150 to 250 dollars, LCD 200 to 400, pro repair 300 to 600 plus.

Your move: careful DIY cable swap, Apple or Authorized repair, or trade in if the quote is high.

5 prevention tips

1. Update your macOS and your heaviest apps monthly.

2. Trim startup items quarterly.

3. Limit tabs/extensions in your browser.

4. Remove old apps fully.

5. Run maintenance monthly with CleanMyMac > Smart Care.

When to contact Apple: knowing it’s beyond DIY

Contact Apple when software fixes do nothing and Apple Diagnostics or display flickers point to hardware. Get a quote first, then weigh repair versus trade-in, and arrive with a fresh backup and AppleCare+ details if you have them.

Now you know why is my MacBook screen flickering lines.