What you can change on your monitor

Your monitor has physical buttons or a menu system that controls brightness, contrast, color temperature, and input source — the cable carrying the picture to your screen. These are separate from your computer's display settings. The monitor's own controls adjust how the hardware displays whatever your computer sends it. Your computer's settings (resolution, refresh rate, scaling) control what your computer actually sends to the monitor.

Most people need to change one of three things: the brightness because the screen is too dim or too bright, the input source because they plugged in a cable but the monitor shows "no signal," or the resolution and refresh rate through their computer because the picture looks blurry or choppy.

Key Takeaways

  • Monitor brightness and contrast are controlled by physical buttons on the monitor itself, usually on the bottom or back, or through an on-screen menu.
  • If your monitor shows "no signal," check that the cable is plugged into both the monitor and the computer, then use the monitor's menu to switch to the correct input source.
  • Resolution and refresh rate are changed in your computer's settings, not on the monitor — Windows uses Display Settings, and Mac uses System Preferences.
  • Most monitors come with a manual or quick-start guide that shows where the buttons are and what each one does.

Finding and using the monitor's physical controls

Look for buttons on the bottom edge or back of your monitor. Most modern monitors have between two and five buttons. One button usually powers the monitor on and off. Another opens the on-screen menu, often labeled "Menu" or shown as three horizontal lines. Some monitors also have dedicated buttons for brightness and volume (if the monitor has speakers).

Press the Menu button to open the on-screen display. You will see a menu appear in the center or corner of your screen with options like Brightness, Contrast, Color Temperature, and Input Source. Use the arrow buttons to move between options, and press Select or OK to change a setting. The exact button names vary by manufacturer — Dell, LG, ASUS, and BenQ all use slightly different layouts.

If you cannot find the buttons, check the back of the monitor near the power cable, or look for a small indentation along the bottom bezel. Some gaming monitors hide buttons under a rubber strip or use touch-sensitive areas instead of physical buttons. Your monitor's manual will show the exact location and function of each button.

Adjusting brightness and contrast

Brightness controls how much light the monitor produces overall. If your screen looks washed out or too dark, brightness is usually the first thing to adjust. Open the on-screen menu, select Brightness, and use the arrow buttons to increase or decrease it. Most monitors show a slider or percentage as you adjust. Start at 50 percent and move up or down depending on your room's lighting.

Contrast controls the difference between the darkest and lightest parts of the image. If dark areas look gray instead of black, or if bright areas look dull, adjust contrast. Contrast is usually set between 50 and 75 percent by default and rarely needs much change. Adjust brightness first, then contrast only if the picture still looks wrong.

Color temperature controls whether the screen looks warm (more orange) or cool (more blue). Most monitors default to a "cool" or "6500K" setting, which matches daylight. If the screen looks too yellow or too blue, you can adjust this in the menu, though most people leave it at the default.

Changing the input source when the monitor shows "no signal"

If you plugged in a cable but the monitor displays "no signal" or a blue screen, the monitor is not receiving a picture from your computer. First, check that the cable is actually plugged into both the monitor and the computer. HDMI cables and DisplayPort cables can look plugged in but not be fully seated — push firmly until you hear or feel a click.

If the cable is plugged in, open the monitor's on-screen menu and look for "Input Source," "Input," or "Signal Source." Select it and you will see a list of options: HDMI 1, HDMI 2, DisplayPort, DVI, or VGA. Choose the input that matches the cable you plugged in. If you are not sure which one, try each option until the picture appears. Once you select the correct input, the monitor will usually remember it the next time you turn it on.

If you have multiple cables plugged in (for example, one from a laptop and one from a desktop), the monitor will only display one at a time. Switch between them using the Input Source menu. This is useful if you share one monitor between two computers.

Changing resolution and refresh rate on Windows

Resolution controls how many pixels your screen displays, which affects how sharp and detailed the picture looks. Refresh rate controls how many times per second the image updates, which affects smoothness — especially noticeable in games or video. Both are set in your computer's operating system, not on the monitor itself.

On Windows, right-click on the desktop and select "Display settings." Scroll down to find "Display resolution" and click the dropdown. Windows will show you the resolutions your monitor supports. Higher numbers (like 1920 × 1080 or 2560 × 1440) are sharper but may make text smaller. Select the resolution that looks clearest to you, then click "explore." Windows will ask if you want to keep the change — click "Keep changes" if the picture looks right.

To change refresh rate on Windows, scroll further down in Display settings and click "Advanced display settings." Look for "Refresh rate" and click the dropdown. Most monitors support 60 Hz (standard) or 144 Hz and higher (for gaming). Higher refresh rates make motion smoother but use more power. Select your preferred refresh rate and click "explore."

Changing resolution and refresh rate on Mac

On Mac, click the Apple menu in the top-left corner and select "System Settings" (or "System Preferences" on older versions). Click "Displays" in the sidebar. You will see "Resolution" options — click the dropdown and select a resolution. Mac usually shows "Scaled" options with descriptions like "More Space" (higher resolution, smaller text) or "Larger Text" (lower resolution, bigger text). Select whichever is most comfortable to read.

To change refresh rate on Mac, click "Refresh rate" in the same Displays window and select your preferred rate. Most Macs default to 60 Hz. If your monitor supports higher refresh rates and you want smoother motion, select the higher option. Click "Done" to explore the change.

Troubleshooting common display problems

If the picture looks blurry, try increasing the resolution in your computer's display settings. Blurriness usually means the resolution is set lower than your monitor's native resolution — the resolution it was designed for. Check your monitor's manual or the manufacturer's website to find the native resolution, then set your computer to match it.

If the picture looks stretched or has black bars on the sides, the aspect ratio is wrong. This usually happens when you connect a monitor with a different shape than your computer expects. In the monitor's on-screen menu, look for "Aspect Ratio" or "Image Size" and select "Full" or "16:9" depending on your monitor's shape. Your monitor's manual will specify which setting is correct.

If colors look wrong (too red, too blue, or washed out), try resetting the monitor to factory defaults. Open the on-screen menu, look for "Reset," "Factory Reset," or "Restore Defaults," and select it. This will return brightness, contrast, and color temperature to their original settings. If colors still look wrong after a reset, the monitor may have a hardware problem.

Frequently Asked Questions

Where are the buttons on my monitor?

Most monitors have buttons on the bottom edge or back panel near the power cable. Some gaming monitors hide buttons under a rubber strip or use touch-sensitive areas. Check your monitor's manual — it will show the exact location and what each button does.

My monitor has no buttons. How do I open the menu?

Some monitors use a joystick or touch-sensitive area instead of buttons. Look for a small indentation or raised area on the bottom bezel, usually in the center. Press or move it to open the on-screen menu. If you still cannot find it, the manual will show you.

I changed the resolution and now everything looks huge. How do I fix it?

Go back to Display Settings (Windows) or Displays (Mac) and select a higher resolution. Higher numbers make text and icons smaller but sharper. If text is too small to read, you can also adjust scaling or zoom separately from resolution — Windows calls this "Scale," and Mac calls it "Larger Text" or "More Space."

Can I damage my monitor by changing these settings?

No. Changing brightness, contrast, resolution, and refresh rate through the menu or your computer's settings will not damage the monitor. The only way to harm a monitor is through physical damage or by using the wrong power cable.

Why does my monitor look different after I restart my computer?

Your computer may have reset to a default resolution or refresh rate. Go back to Display Settings or Displays and set it again to your preferred option. If this keeps happening, your graphics driver may need an update — check the manufacturer's website for your graphics card (NVIDIA, AMD, or Intel).