How to prevent your car window from fogging up

Driving on the road with a foggy window can be both irritating as well as dangerous. Especially in the winter season, you could start driving and in just a few minutes, you suddenly realize that you can’t see forward. But if you know how to prevent your windshield from being foggy, then, you will be on the safe side.

While foggy car windows are not the only thing that can be a serious nuisance for being foggy; your motorcycle mask, scuba mask, and sunglasses can get foggy and be irritable.

If you are faced with a foggy situation, the fast and convenient way is to purchase a window defogger and use it. Or better still, use some of the products you have in your home. ChrisFix has in his video “How to Prevent your Car Windows from Fogging Up” explained how each of the products gives diverse results.

What is fog? What causes it?

In order to deal with fog, you need to understand what comprises fog. To do that, you will need a special microscope camera that can zoom in and give a microscopic perspective of fog.

If you take the microscope and zoom in at 50x magnification, you will clearly see the individual water droplets. But if you enhance the magnification to about 500, the experience will be even awesome, as the little droplets you saw earlier will turn out to be larger.

You will notice that you can also see tons of water drops which creates difficulty when seeing through a foggy window. Therefore, fog occurs when the air has a lot of moisture that evidently sticks on something.

Ways of preventing fog

Basically, there are two ways you can use to prevent fog:

  • Remove moisture out of the air inside the vehicle. To do that, you will need to set your air-conditioner to Defrost mode. The air conditioner normally cools and pulls water out of the air inside the vehicle. In case, your air conditioner fails to work or the windows keep fogging up, you will need to try the other trick.
  • The other method that can solve the fog issue is to create a barrier between the glass and the air so that fog fails to stick to the glass. This method is what the article is all about; as the YouTuber clear demonstrates through the video clip.

Items needed        

Mouthwash Avocado Spit
Bar soap Onion Toothpaste
Steamy hot water pots



  • Choose a car window for the test; preferably the back part.
  • Clean that particular window to ascertain degree so as to prevent fog from sticking. Normally, it is harder for the fog to stick on a cleaner window.
  • After drying, divide the window into 6 sections for testing these products and add another section for the control area.
  • Apply the product onto the window surface using a paper towel. You will rub each product on its area and then, buff it off using another fresh towel till you can clearly see through the window.
  • To saturate the moisture inside the car, you will use the steamy hot water pots. Place the hot water pots close to the window so that you have maximum humidity that will exhibit the worst-case scenario of fog.


As ChrisFix observed from the experiment he carried out in his YouTube video, most products displayed similar performances. The control area that remained untreated became fogged up. Also, The mouthwash and the bar soap looked like the untreated area. The avocado, spit and onion didn’t give good results. It is only the toothpaste that fantastically worked out as it remained clear even after intensive fogging.

To wrap it up

Basically, if you don’t have a de-fogger, you can use the toothpaste which also gives good results. Other than the car windshield, you can apply toothpaste on your ski mask, motorcycle mask, scuba mask or even sunglasses when you are on a vacation. Likewise, you can prevent your bathroom mirror or anything else from fogging up.