The Best Lightweight Antivirus Software for 2024

Whether you’re using a computer with limited processing power or simply want software that won’t slow you down, check out our 5 picks for the best lightweight antivirus software.
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Best Overall

4.3
Editorial Rating
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On Norton 360 Antivirus's website

Norton 360 Antivirus
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Best for Fast Scans

5.0
Editorial Rating
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On Avast's website

Avast
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Best for Mobile Coverage

5.0
Editorial Rating
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On Avira's website

Avira
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Best Free

4.6
Editorial Rating
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On Bitdefender's website

Bitdefender
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Best for Macs

4.1
Editorial Rating
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On MacKeeper's website

MacKeeper
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Our top choice for the best lightweight antivirus is Norton, as it offers a lot of features and strong protection scores without slowing your device down. Antivirus software for low-end devices can be hard to find, especially when they all claim to be fast and undetectable.

Other choices include Avast for fast scans and Avira for a lightweight mobile app. Bitdefender has a free tier that offers consistently high malware scans without taking up resources. Finally, MacKeeper comes with macOS optimization tools for speeding up an overloaded device.

Read on to see what we liked, what we didn’t, and which of these lightweight software providers is right for you.

In this article
The best lightweight antivirus software
How we tested the best lightweight antivirus software
Norton: Best overall
Avast: Best for fast scans
Avira: Best for mobile coverage
Bitdefender: Best free antivirus
MacKeeper: Best for Macs only
What should I look for in a lightweight antivirus?
What antiviruses should I avoid?
FAQs
Bottom line

The best lightweight antivirus software for 2024

Top 5 lightweight antivirus products compared

Star rating
4.3
5.0
5.0
4.6
4.1
Starting price $29.99/yr (first year only) Free Free Free Free
Max number of protected devices 10 30 25 10 3
EICAR test results 3/3 3/3 3/3 3/3 2/3
Malware scans Manual and scheduled Manual and scheduled Manual and scheduled Manual and real time Manual and scheduled
Real-time protection
Firewall
Phishing protection
Ransomware protection
Performance impact* 11.5 9.3 9.4 9.7 N/A
Extras Parental controls, dark web monitoring, and more VPN, computer tune-up, browser cleaner, disk cleaner, driver updater Password manager, VPN, ad and tracker blocker, identity protection Social network protection, file shredder, and more VPN, data breach monitoring, ad blocker
Compatibility Android, iOS, Windows, macOS Android, iOS, Windows, macOS Android, iOS, Windows, macOS Android, iOS, Windows, macOS macOS
Learn more Get Norton

Read Norton Review

Get Avast

Read Avast Review

Get Avira

Read Avira Review

Get Bitdefender

Read Bitdefender Review

Get MacKeeper

Read MacKeeper Review

*The lower the performance impact score, the lighter the antivirus.

How we test and rate antivirus software

We use our proprietary grading rubric in all of our testing, which considers ease-of-use, third-party testing scores, internal testing scores, price, compatibility, and features offered, among other metrics. 

This means that our testing process is designed to ensure that the product isn't too confusing, protects as it claims, and offers you a lot for a reasonable price. We download and run each program on our own computers on home networks, just like you would. Our ratings reflect the real-world performance of the antivirus product. This ensures that we can recreate a similar experience for you and give our best advice on whether or not it's worthwhile.

To learn more about how we test, check out our full antivirus testing methodology here.

Third-party testing

Third-party testing is an important evaluation tool that can help you decide which antivirus program is right for you. AV-TEST, AV-Comparatives, and SE Labs charge companies to submit their products for testing, which are then rigorously tested.

The results are published without the antivirus company having any say in their presentation. This allows you, the consumer, to see how the software copes with computer viruses and malware.

We also evaluate antivirus software ourselves using third-party test scores and a system called EICAR, which allows us to test against malware, potentially unwanted programs (PUPs), and phishing attempts. EICAR testing brings a deeper level of understanding to a product’s effectiveness by showing how it works against threats other than malware.

We retest products frequently to ensure that our information is correct. If a product gets better or worse, we let you know.

Norton: Best overall

Enjoy Norton’s 100% Virus Protection Promise
4.3
Editorial Rating
Learn More
On Norton 360 Antivirus's website
Antivirus Software
Norton 360 Antivirus
Save up to 58% your first year
  • 4 plans available, all including antivirus, malware, ransomware, and hacking protection, Cloud backup, and a secure password manager
  • Option to add VPN connection, dark web monitoring, privacy monitoring, and more
  • Compatible with Windows, Mac, Android, and iOS on up to 10 devices depending on plan

Who it’s best for

Norton is great for anyone who wants a lightweight antivirus with plenty of additional features. Usually, features have to be sacrificed for the sake of processing power, but Norton’s features are light enough not to impact your system. You’ll find extras like Norton’s VPN, identity theft protection, and cloud storage.

No matter if you’re an individual with a single computer or in a large family with a laptop for each person, Norton can cover your devices, as its Ultimate Plus plan protects unlimited devices.

Full suite of Norton security tools

What we liked

For as much as it offers, Norton is still a pretty lightweight antivirus option. Users looking for an all-in-one solution will enjoy Norton 360’s features, such as cloud storage, a password manager, credit monitoring, parental controls, and more. If you have a lower-end device with limited processing power, Norton has protection features like cloud storage and a password manager, which have minimal CPU or RAM impact.

When we tested Norton’s usability, we found it intuitive and helpful. Sometimes, security products are difficult to navigate, but Norton makes using its product easy for anyone. The language is clear and geared toward non-technical users, and anyone should be able to open the dashboard and use the program.

What we didn’t like

Norton is a great product, but our biggest complaint is always its price. While Norton has reasonably priced tiers on all of its products, if you need broad coverage for a family, other antivirus programs will be more affordable.

Even when you consider the savings you’ll get from bundling Norton’s antivirus, a virtual private network (VPN), and identity theft protection into one package, you’re still likely to pay a lot.

Test results

Norton
AV-TEST Windows score 16.5/18
AV-TEST macOS score 18/18
AV-TEST Android score 18/18
AV-Comparatives malware protection score 99.97%
SE Labs results 99%
EICAR score 3/3
Learn more Get Norton

Read Norton Review

Avast: Best for fast scans

5.0
Editorial Rating
Learn More
On Avast's website
Antivirus Software
Avast
  • Perfect third-party test results, verifying comprehensive antivirus, ransomware, and malware protection
  • Includes advanced security features like a VPN, firewall, data breach alerts, privacy tools, device optimization, and more
  • Lackluster customer support

Who it’s best for

Avast is good for users looking for an antivirus that offers faster scans. In our testing, a smart scan took 40 seconds, while a deep scan ran just over 5 minutes. This means that even if your device is low end, the disruption to your work won’t be as long. Considering that some heavier antivirus products can take hours, Avast offers top-rated protection with less impact on system performance.

Don’t assume that Avast’s speed makes it unsafe. It comes with excellent protection scores from third-party testers and passes our internal tests with excellent results.

Avast deep scan running

What we liked

There’s a lot we like about Avast. Its free tier provides top-notch antivirus protection that’s accessible to everyone. It’s a perfect product for anyone on a tight budget. Even though there are a variety of free antivirus products, Avast stands out to us because of its performance.

Not only is the impact score the lowest on our list, but it’s also one of the most robust, free products available. For anyone wanting more, Avast and Avast One’s upgraded versions are still budget friendly and include so many features. We’re always pleasantly surprised when we see all that Avast can do.

What we didn’t like

Despite all of the great things we love about Avast, it doesn’t offer parental controls. That may or may not be a deal breaker for you, but we were hoping for something, even if it’s only in the Family plan.

Test results

Avast
AV-TEST Windows score 18/18
AV-TEST macOS score 18/18
AV-TEST Android score 18/18
AV-Comparatives malware protection score 99.95%
SE Labs results 100%
EICAR score 3/3
Learn more Get Avast

Read Avast Review

Avira: Best for mobile coverage

5.0
Editorial Rating
Learn More
On Avira's website
Antivirus Software
Avira
  • Tried and true real-time antivirus protection
  • Free plan comes with antivirus protection, software updates, and web protection
  • Can be expensive for multi-device coverage

Who it’s best for

Avira offers great antivirus coverage for Android and iOS. Its free mobile app also includes a VPN, web protection, an operating system (OS) updater, contact backup, and anti-theft protection. All of this plus a low impact score makes Avira a good choice for mobile protection.

Avira Prime firewall settings.

What we liked

Avira tested well for us, running fast scans, returning impressive third-party results, and covering mobile devices with ease. Its free plan has various features, including performance enhancement tools and web protection. What really stood out to us, however, was the mobile protection.

Avira’s VPN is an invaluable tool for mobile devices, especially if you connect to any kind of shared Wi-Fi network, like in a coffee shop or library. This offers lightweight protection even while you’re away from home. While the features differ from iOS to Android, the fact that you’re getting protection geared toward your device’s needs is one we like.

What we didn’t like

If you decide to upgrade Avira, which you may need if you have multiple devices to cover, the protection cost can get a little pricey. Subscription prices are based on how many devices you want to cover and what features you want to include.

Test results

Avira
AV-TEST Windows score 17.5/18
AV-TEST macOS score 17.5/18
AV-TEST Android score 17/18
AV-Comparatives malware protection score 99.95%
SE Labs results 93%
EICAR score 3/3
Learn more Get Avira

Read Avira Review

Bitdefender: Best free antivirus

4.6
Editorial Rating
Learn More
On Bitdefender's website
Antivirus Software
Bitdefender
  • Super reliable antivirus software with a non-intrusive free version
  • Simple yet powerful interface tools
  • Perfect protection score in third-party tests
  • Slow scans compared to other options

Who it’s best for

While there are other free antivirus options on this list, Bitdefender’s free plan is one of the best, especially for its malware detection rate with minimal device impact. Bitdefender consistently returns excellent third-party scores when tested. We found it to be lightweight and powerful with low CPU usage.

Even though there are several free products in this review, Bitdefender has a comprehensive approach to security. It uses award-winning technology in its real-time protection to keep you safe from new and emerging threats.

On Windows devices, Bitdefender offers Ransomware Remediation, a ransomware blocker that also restores encrypted files.

What we liked

Bitdefender includes device protection as well as safe online shopping and phishing protection in its free tier. Not all free antivirus services are made the same, so you have to make sure whatever product you choose comes from a reputable company. Bitdefender delivers award-winning protection with third-party testing scores to back up its claims.

We also like that it strikes a nice balance between alerting you to issues and not spamming you with too much information. It’s that kind of efficiency that Bitdefender offers in its free product. Of course, you could upgrade for more features, but if you want a free antivirus that’s guaranteed to protect you, Bitdefender is quite the contender.

What we didn’t like

We did find Bitdefender to be a bit lacking in its offerings for macOS and iOS. Like a lot of other antivirus products, the Apple operating systems don’t get as much love as the Windows-based ones. Apple users want quality protection and enhancements too, so having fewer features and options is always annoying.

Test results

Bitdefender
AV-TEST Windows score 18/18
AV-TEST macOS score 18/18
AV-TEST Android score 18/18
AV-Comparatives malware protection score 99.92%
SE Labs results 100%
EICAR score 3/3
Learn more Get Bitdefender

Read Bitdefender Review

MacKeeper: Best for Macs only

4.1
Editorial Rating
Learn More
On MacKeeper's website
Antivirus Software
MacKeeper
  • ID Theft Guard feature scans your emails
  • Easy, fast, knowledgeable customer support
  • Customer support requires a tech to access your device

Who it’s best for

MacKeeper is a great solution for macOS users who want security software built specifically for their device. MacKeeper has had its ups and downs, but within the past few years it has become a useful form of security for Mac users.

With performance enhancement tools, patch management, and hard drive cleanup it can help optimize your device to run faster.

MacKeeper in the process of running an antivirus scan.

What we liked

MacKeeper is one of a handful of security programs built exclusively for macOS. Third-party test scores returned solid protection results, and our testing showed MacKeeper to be excellent at malware protection. MacKeeper’s VPN is so lightweight we never notice it working in the background (and we tested it extensively).

We’re also fans of MacKeeper’s extras, like the patch management. Software developers release patches every so often as updates to keep the program working smoothly and securely. MacKeeper identifies those updates and installs them for you. It’s such a simple service, but it increases your security by always keeping your apps current.

What we didn’t like

MacKeeper doesn’t have extensive third-party testing, so we were unable to find an impact score or CPU usage. From experience, we know it’s lightweight, but it would be nice if the information was readily available.

Test results

MacKeeper
AV-TEST Windows score N/A
AV-TEST macOS score 17.5/18
AV-TEST Android score N/A
AV-Comparatives malware protection score N/A
SE Labs results N/A
EICAR score 2/3
Learn more Get MacKeeper

Read MacKeeper Review

What should I look for in a lightweight antivirus?

When we reviewed antivirus software, the most important aspects we looked for included fast scans, excellent protection scores, useful features, and reasonable pricing.

Fast scans that also allow you to use your device unencumbered are the top trademark of a lightweight antivirus. Most of our choices take less than 5 minutes, and none take more than 30 minutes for a full scan. This means that even if the scan does slow down your device it will only be for a short time and cause minimal disruption.

You’ll also want an AV with great third-party testing scores. All of our choices passed our internal tests and were highly rated on AV-TEST, AV-Comparatives, and SE Labs.

Useful features can reduce your overall monthly security costs by combining antivirus with a password manager, a VPN, cloud storage, device optimization tools, and more. Of course you’ll want antivirus software that fits your monthly budget. While many of our choices here have a free tier, options with reasonable pricing are also available for anyone who wants a little more.

What antiviruses should I avoid?

If you want something lightweight and easy, avoid a bulky antivirus with high CPU usage, buggy or long scans, and so-so protection scores. We’ve listed some of the ones we found to perform poorly, especially with scans, protection scores, or generally difficult or outdated interfaces.

  • Iolo
  • Kaspersky
  • PC Matic
  • ClamWin
  • HitmanPro.Alert
  • CleanMyMac X

FAQs


+

What is the most lightweight antivirus?

Avast is the most lightweight antivirus. It offers the lowest impact score, which means it can run smoothly in the background while you continue to work on your computer. However, Norton does offer slightly more features for a slight increase in processing requirements.


+

What is a lightweight alternative to Windows Defender?

Avast, Avira, and Bitdefender all have low-impact scores and free tiers. Windows Defender’s most significant appeal is that it is free, so why not replace it with a quality free antivirus that offers additional protection and features?


+

Can I still use an antivirus on a low-end device?

While opinions might be mixed about using additional antivirus protection on a low-end device, you can as long as the software is lightweight and you aren’t trying to do more processing than the device can handle.


+

What are the best antivirus features for a low-end device?

When protecting low-end devices, or devices with lower processing power, you’ll want to make sure your antivirus software isn’t too elaborate. Some features you’ll want to consider:

  • Real-time protection to stop viruses from slowing your device.
  • Manual and scheduled scans so you have control over when scans happen.
  • Ransomware and phishing protection.
  • Small extras like cloud storage.
  • Performance enhancement tools that can help speed your device up.

Bottom line: The best lightweight antivirus programs

Norton, Avast, Avira, Bitdefender, and MacKeeper are all lightweight antivirus solutions that show excellent performance and protection.

Whether you’re using a computer with limited processing power or just don’t want a heavy antivirus bogging down your CPU usage, you can still get top-tier protection without sacrificing memory space.

Enjoy Norton’s 100% Virus Protection Promise
4.3
Editorial Rating
Learn More
On Norton 360 Antivirus's website
Antivirus Software
Norton 360 Antivirus
Save up to 58% your first year
  • 4 plans available, all including antivirus, malware, ransomware, and hacking protection, Cloud backup, and a secure password manager
  • Option to add VPN connection, dark web monitoring, privacy monitoring, and more
  • Compatible with Windows, Mac, Android, and iOS on up to 10 devices depending on plan
Author Details
Mary is a seasoned cybersecurity writer with over seven years of experience. With a B.S. in Liberal Arts from Clarion University and an M.F.A. in Creative Writing from Point Park University, she educates audiences on scams, antivirus software, and more. Her passion lies in educating audiences on helpful ways to protect their data.