Do You Need To Protect Your Computer From Magnets?

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computers and magnetsMagnets are kind of magic. Okay, not really – but to the layman they a bit bewildering. The magnetic field they emit is entirely undetectable by human senses. One can only imagine the confusion our ancestors must have felt when they first discovered them.

Today we have an understanding of how magnets work, but that doesn’t mean they no longer trouble us. A magnet has the potential to cause all sorts of issues for electronic devices. Do you really need to protect your computer from magnets, or is this concern overblown?

Why Magnets Might Harm Your PC

computers and magnets

There are two ways in which a magnet might harm a computer.

One is through loss of data on magnetic media. This includes traditional mechanical hard drives, floppy disks and any other magnetic storage media. These components are potentially vulnerable because they use magnetization as a means of recording data, but the magnetic forces are controlled. A strong magnetic field could wipe data by interacting with and changing the magnetization of the drive.

The second potential issue is a magnet’s field potential to generate a charge in objects around it. Recently I wrote an article about wireless charging, an innovation that uses this fact to transmit power wirelessly over very short distances. It’s possible the same effect (if substantially amplified) could induce a charge in your computer’s electronics, frying them. Electromagnetic pulse weapons work on the same principle.

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Should You Be Worried About Magnets?

can magnets hurt computers

Not generally. Magnets and devices emitting magnetic fields exist everywhere in modern life, but most of these are not capable of generating a magnetic field that is strong enough to have an effect on electronics.

The idea that magnets could cause harm seems to be popularized by the use of magnets as a means to erase floppy disk. Many fell into believing that this meant any magnet could be used for the job. In reality, a rather strong magnet – far stronger than anything you’ll find on your fridge – is required to reliably erase a floppy disk.

Mechanical hard drives actually have magnets in them. That’s how data is written to the magnetic disk. To cause any damage you’d have to expose the drive to an even stronger magnetic field. That’s something you’re unlikely to encounter outside of a scientific laboratory or a nuclear apocalypse.

Solid state memory, including solid state hard drives and modern RAM/ROM, don’t use magnetic fields to store data. They will suffer no ill effects from a nearby magnetic field of moderate strength.

Most computer components, including solid state memory, could be damaged by a magnetic field strong enough to induce a charge – however, this is yet again in “laboratory or nuclear apocalypse” territory. You do not have to worry about this is the typical home or office.

A Few Problem Areas

computers and magnets

Subwoofers use strong magnets that could erase magnetic storage media. Many people have placed computers near subwoofers with no ill effects, but most subwoofers aren’t very powerful and don’t include a strong enough magnet. Only large, powerful subwoofers are an issue.

Old CRTs can be damaged by magnets. Most distortions in a CRT’s picture due to magnetic fields can be removed by de-gaussing it, but permanent damage is possible with a strong magnet. New LCD monitors do not have the same vulnerability.

Cables can also be a problem area because they are sometimes entirely unshielded, leaving them exposed to interference. Audio cables used with PCs are the most common victims of this problem. Interference will not damage the cable but it does degrade the quality of any signal passed through it. The only way to fix this problem is by purchasing new cables with better shielding.


Most magnets are not a problem. A refrigerator magnet is not a threat and even the magnets in most household subwoofers are unlikely to cause a problem. Magnetic fields are just too weak to be a serious issue. It takes a very powerful magnet, or a huge burst of energy, to generate a magnetic field strong enough to damage modern computer electronics.

Image Credit: Windell Oskey, Alex and Rachel Johnson

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19 Comments - Write a Comment


salim benhouhou

thanks for the explanation Matt



I am aware of one case where a desktop pc was having intermittent “issues” in performance that was caused by having a large sheet of magnet stuck to the side of the case. I believe it was a pizza delivery sign intended for a car door, and the strange issues with the pc stopped after the sign was removed.



I did encounter a client’s computer with problems that were no longer present once a refrigerator magnet was removed from the computer tower case. But returned when it was replaced. The irony of the whole thing was the magnet was a magnetic business card for my mother’s business.


Roger Stoddard

I have not heard of magnets affecting computers before but it does make sense to me.


Joel Lee

I was always aware of this myth but now I’m a bit more at ease. Thanks Matt.


Adrian Rea

Of course the magnets can wipe data. As a company we protect from data theft by degaussing hard drives which sends high magnetic levels through the drives


General Melchett

I was given a magnetic business card the other day and took great care to put it in one pocket, while cramming both my phones, my wallet (containing bank cards) and my car keys (with remote control unit) into the other.
Most uncomfortable, and now it seems I needn’t have bothered!


Edwin Williams

Ah thanks for the information! It clears up a lot of stuff I had about magnets and computers!


Igor Rizvi?

Liquid crystals are EXTREMLEY sensitive to electric field changes, so you don’t even need a magnet to see how sensitive they are. Try this; put a piece of “scotch magic brand” (tm 3M) tape (the kind you can write on) and stick it LIGHTLY onto the face of your LCD screen, leaving one end NOT stuck down so that you can pull it back off.

Whith the monitor UNPLUGGED and the VGA connector OFF rapidly pull the tape off at about a 45 degree angle away from the LCD screen.

You will see many of your LCD “pixels come to life”

That is just from non-contact static electricity.

Now if you were to take say, the magnet out of the magnetron in a microwave oven and pass it over a running LCD monitor you may induce enough magnetic pressure to short out the transistors and diodes in the Liquid crystal display

The second method that the magnet will cause problems is for the same reason that motors spin.

If you MOVE a magnetic field across a conductor like a wire or a circuit trace (and there are 10’s of thousands of circuit traces embedded in the LCD screen) then you will magnetically induce an electric potential on those conductors and circuit traces — you might short stuff out by turning something on when something next to it should be off

Bottom line?

Don’t do it

Igor Rizvi?

also if your interested,go to wikipedia and check out the Hall effect.



harm your computer??
i’d say, magnets won’t really harm your computer as a whole,
but magnets can grossly damage you hdd’s


Ashwin Ramesh

I always knew something about this, but this article makes it clearer. Thanks Matt!


Harry Barnes

phew, my subwoofer is right next to my computer so I got worried for a sec!


Harshit Jain

I even saw this on discovery channel where a man tries even the magnet used to lift magnetic material from garbage to see it’s effect on a laptop’s HDD. And it didn’t survive.


Keith Swartz

Good article. I have had that question i=at the back of my mind. I am glad MakeUseOf has brought it to the front and answered it once and for all! Thank you. No, I really, sincerely do thank you!


Eath Chantrea

Thank for informations!


Stephanie w

Thanks – this is really interesting. Is the magnetic interference the reason I sometimes hear phantom radio sound through my speakers?


Jeremiah Iliffe

Thanks, I used to be really scared of this


Nikhil Chandak

I don’t think so that I will have to protect my computer with magnets ..
as if I hv antivirus programs & softwares in my PC

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