10 Lightest Antivirus On Memory Usage During Idle and Scanning

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If you’re looking for an antivirus that is light on memory during idle and scanning, here are the top antivirus that you might find useful for your slow computer. Remember, light doesn’t mean better detection rate, vice versa, heavy on memory usage doesn’t mean it is a good antivirus either.

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The best antivirus is the one you feel most comfortable in, the one that allows you to play Dota or Diablo without lagging it. Then again, in today’s ample computing world, lagging is mostly due to your broadband internet speed.

For your information, Norton may not be the fastest but it is still one of my favorites. With today’s computing power, processing consumption used by most anti-viruses is not an issue. However, if you are on a very old and sluggish system, selecting an antivirus with the least taxing on the system is a must.

Below is the complete list of some of the most popular antivirus and its usage on system resources. The table does not include detection rate and features. For those in the dark, some antivirus has a ‘gaming mode’ where it will reduce the resources required when you are playing Dota or Counter Strike.

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Top 5 Lightest Antivirus on Memory during Idle and Scanning

Do you find this information useful? Remember to share this with your friends on Facebook and twitter. Thanks. Below is a complete list of some of the most popular antivirus and its usage on system resources. The table does not include detection rate and features. The top 5 lowest resource grabbing antiviruses based on my own test are.

1. Top 5 Lightest Antivirus On Memory (Idle)

  • Avast Free Antivirus – 9KB
  • AVG Antivirus Free Edition – 9.8KB
  • Norton Antivirus – 10KB
  • Norton 360 – 11.5KB
  • Kaspersky Pure – 14KB

2. Top 5 Lightest Antivirus On Memory (Scanning)

  • Avast Free Antivirus – 62KB
  • TrendMicro Internet Security – 67KB
  • CA Antivirus Plus – 78KB
  • Norton Antivirus – 77KB
  • Kaspersky Pure – 82KB
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Antivirus Memory Usage and Processor Consumption Comparison

Memory Usage (MB)
smaller better
Scan Speed (MB/s)
bigger better

Avast Antivirus Pro


Panda Antivirus Pro


Norton Antivirus


BitDefender Antivirus Pro


Avira AntiVir Premium


Kaspersky Antivirus


AVG Antivirus


Trend Titanium Antivirus


F-Secure Antivirus


3. Top 10 Most Devastating Computer Viruses

4. Top 10 Antivirus Market Share

Global market share held by the leading Windows antivirus application vendors in January 2014, this includes both free and paid, which explains why Microsoft is dominating the computer security market with their free antivirus.

Image source: Statista


  1. Gravatar
    Raymond [ Reply ]

    Which FREE Antivirus is the Lightest on System Memory Usage?

  2. Gravatar
    Harsh Singh [ Reply ]

    Top 10 Lightest Antivirus On Memory (Scanning) Avast Free Antivirus ?

    • Gravatar
      Squidward [ Reply ]

      It really aint, took a whole gb of ram when I last used it. Now my bitdefender is acting funny and I have to change again

  3. Gravatar
    ZamZam [ Reply ]

    Fastest PC & Mac Virus Protection

  4. Gravatar
    Michele McDonough [ Reply ]

    What is the Least RAM Intensive Virus Protection Software?

    • Gravatar

      I would try Clamwin

      • Gravatar

        ClamWin doesn’t have on-access (real-time) protection. It mentioned in it’s website.

  5. Gravatar
    Álvaro [ Reply ]

    Zoner is the best.

  6. Gravatar
    kieran [ Reply ]

    kaspersky was using 100% cpu when scanning, and slowed my computer down too much in general so i just removed it

    • Gravatar

      And i was have three days before big security isue with KAVFree.
      Found virus trojan and need buy full version of KAV for changes in OS. <<< WTF Kaspersky???
      And now i have very slow OS starts (with or without Malwarebytes, this is not issue of slow start) Then i install Malwarebyte trial and that found FIVE other viruses!
      KAVFree is for me now untrusted AV. And i take many years KAV like best secuirty choices.
      I think this is on purpose from Microsoft directly, to discourage peoples to use KAV, due to
      politics reasons.
      On some workstations i use free AVses, where is low security risk. Few month ago i was
      very delighted with free version of KAV, and now that issues :(

    • Gravatar

      I can confirm, I have been having this problem for last few months now. KasperSky uses 100% disk usage whenever it scans, updates in the background or does anything really.

  7. Gravatar

    AFTER scanning the file system the AVG 2020 Free scanner process was using 465 MB. So much for “light memory usage”.

    • Gravatar

      Most antivirus are like that. Try using them for days without restart (usually I just hibernate my computer for faster startup), they will consume hundreds MB of your RAM.

  8. Gravatar

    I think Panda antivirus is the lightest and with the simplist interface…

  9. Gravatar

    i think eset is fairly lightweight.. j always liked it although my subscription ran out.. i used it for a year with no prolems

  10. Gravatar

    where is Webroot ??

    Webroot Secure Anywhere is ligher AV on World

  11. Gravatar

    I remember minimal RAM consumption was AVIRA but with really objectionable 1/6 screen adverts. But be aware if you finding low mem consuption, you must find alternative which
    have good virus checking test ;-)

  12. Gravatar

    Well, this was paid for. Norton in the top 100 even? it will consume 2 gb if it can

  13. Gravatar

    Webroot is untouchable regarding low footprint.

  14. Gravatar

    your review is a joke AVAST / AVG / others you list are some of the heaviest on the market

    • Gravatar

      That’s right . Those are the most ram hungriest antivirus in the world

    • Gravatar

      AVAST is a lead anchor in the PC’s. I’m searching here because I have it installed in a laptop with 2Gb RAM and it seems to be doped turtle

  15. Gravatar

    Using Bitdefender Free, and it sucks more than 2GB on file transfer activity. WTF!

  16. Gravatar
    Tim Locke [ Reply ]


    • Gravatar

      Why many website include avast and avg, every time theres a light antivirus review? Paid?

      • Gravatar
        Ngan Tengyuen [ Reply ]

        Do they even have a paid review program? No affiliate links too. I can bet you if the list is some other antivirus, there will someone just like you complain about it.

  17. Gravatar
    HENDRO [ Reply ]

    How about Webroot Antivirus?

  18. Gravatar

    I have Eset for our two PC home network. Looking in Task Master with my PC at idle and no apps open. Eset is using 71MB of memory. Definitely a Hog!

  19. Gravatar
    TS Garp [ Reply ]

    To be honest, a good antivirus loads its fingerprint database in memory to be able to scan faster. Memory usage for me is less important than detecting a virus before it can do any harm. In fact, if AV programs store their database in swap, it will slow down your PC overall, and it would allow a virus to do harm before it would be detected.
    Check for good AV at https://www.av-comparatives.org/ and https://www.av-test.org/en/antivirus/home-windows/

  20. Gravatar

    use smadav if you want lightweight effective antivirus with usb security and real time protection its free. 2.3mb ram usage only

  21. Gravatar
    Kashif Hassan [ Reply ]

    Norton Antivirus 2011 ???? is this comparison 8 year old ?

  22. Gravatar
    Douglas Thompson [ Reply ]

    When I am in the middle of teaching a Zoom class, a message will pop up from Norton saying that while my computer is “idle” it’s going to perform background tasks. And it does! Sometimes using so much of my resources that my audio completely goes out.

  23. Gravatar
    Zarzour [ Reply ]

    The best and lightest free antivirus software is NAS!!
    NAS -> No Antivirus Software! :-)

  24. Gravatar

    use Ram Antivirus it works smooth ,multitasking,light weighted and use machine learning technology to detect new born malware best antivirus for windows 8 and windows 10

  25. Gravatar
    nooobx1000 [ Reply ]

    does windows defender uses high ram
    which is free antivirus use less ram ?

  26. Gravatar

    with nothing else running, avast runs my fans and 100% on win7……how to fix constant fan running!! pleasssssssssse make it quiet again.

    • Gravatar
      Sir Henry [ Reply ]

      Cut the wires to the fan… problem solved lad!

  27. Gravatar

    I can confirm, I have been having this problem for last few months now. KasperSky uses 100% disk usage whenever it scans, updates in the background or does anything really.

  28. Gravatar

    Webroot must at least be in the top 3 of most light.

  29. Gravatar
    gqqnbig [ Reply ]

    Are you sure the unit is KB? I don’t believe the memory usage can be a few KB. Is it MB?

  30. Gravatar
    Anti Virus [ Reply ]

    AVG only 29.6 MB usage???
    On my computer it uses 154.7 MB out of 4 GB Ram…

  31. Gravatar
    365cent [ Reply ]

    Clamwin is the best, works great for me. (Although it doesn’t have real-time protection

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