Online security should be available to everyone, but some devices struggle with modern free and paid antivirus software. This is often due to limited processing power with an older CPU, limited memory, or a low storage capacity. Whatever the case, using modern antivirus software on low-resource devices can be challenging. This makes finding a free antivirus that’s also lightweight all the more imperative.
In this post, we detail the results of our research into the best free antivirus programs for low-resource devices. We prioritized those that will have minimal impact on your device’s CPU, RAM, and storage. Where possible, we’ve looked for free antivirus solutions that offer cloud-based scanning to minimize local resource usage. You’ll find reviews of each free antivirus, their respective pros and cons, and insight into our testing methodology.
Need to make a quick decision? Here’s a brief rundown of the best free antivirus software for low-resource devices:
- Avast One Basic: Best free antivirus for low-resource devices. Very lightweight design and includes ransomware protection and a VPN with 5GB of weekly data.
- Bitdefender Antivirus Free: Passed performance testing with flying colors. Doesn’t compromise on protection either but remains very easy to use and has live support.
- Panda Free Antivirus: Cloud-based protection for low-resource devices. Impressive protection scores from independent testing labs and includes a dark web scanner.
- Avira Free Antivirus: Real-time protection and lots of extras including a password manager and VPN. User-friendly app interface and excellent protection score in testing.
- AVG Antivirus Free: Provides multiple layers of protection for reliably blocking a variety of malware threats. Lightweight antivirus app that very rarely produces false positives.
- Microsoft Defender Antivirus: Pre-installed on Windows devices. Balances strong, real-time protection with smooth performance – ideal for low-resource devices.
Criteria for the best free antivirus for low-resource devices
First and foremost, we’re looking for antivirus programs that are free and lightweight enough to be compatible with low-resource devices. Yet we can’t ignore the protection they offer, nor the features that are included. Here’s what we prioritized:
- Lightweight app with minimal impact on device resources
- Cloud-based scanning to reduce resource consumption
- Detects and blocks a variety of viruses and malware
- User-friendly app interface and help resources
- Free extras such as a password manager
- Genuinely free as opposed to a free trial
Best free antivirus for low-resource devices
Here’s our list of the best free antivirus software for low-resource devices:
1. Avast One Basic
Avast One Basic provides an impressive number of features for being a free antivirus. Aside from blocking viruses and malware, there’s ransomware protection for your files – something that’s not included with many free antivirus programs. Also impressive is a free VPN with up to 5 GB of data each week. Avast scored full marks for both protection and performance in our in-house testing. High scores from independent testing labs back this up.
If you’re on Windows or Android, you can use Avast One Basic to improve your device’s performance by optimizing the background activity of apps and clearing junk files. Upgrading to a paid plan adds optimization tools, from disk cleanup to automatic updates for your PC’s drivers. There’s not much to blame with Avast One Basic, but like most free antivirus offerings, it only covers one device, which might not suit everyone’s needs.
You can find Avast One Basic apps for Windows, Mac, Android, and iOS.
Pros:
- Lightweight so ideal for low-resource devices
- Includes ransomware protection for your files
- Free VPN with a generous data allowance
Cons:
- Limited to a single device
BEST FREE ANTIVIRUS FOR LOW-RESOURCE DEVICES:Avast One Basic not only protects against viruses and malware, but ransomware. Extras include an advanced firewall and VPN. Very strong protection and performance scores in testing.
Read our full Avast Antivirus review.
2. Bitdefender Antivirus Free
Bitdefender Antivirus Free makes a point of stating that it’s lightweight and won’t consume a lot of your system resources. Our testing found this accurate, and AV-Test and AV-Comparatives have also recognized Bitdefender’s performance. Where it really shines, however, is in the protection it provides. It keeps you safe from most types of malware but doesn’t secure files from ransomware – a feature reserved for the paid version.
One way in which Bitdefender Antivirus Free stands out from most free antivirus offerings is the fact that it provides live customer support even for non-paying users. This is great if it’s your first time using an antivirus and you don’t want to be limited to a community forum or an FAQ section. It would be nice to see the web tracker blocker available for the free version, but it’s hard to complain when you consider the level of protection on offer at no cost.
Bitdefender Antivirus Free is available via Windows, MacOS, and Android apps.
Pros:
- Live customer support available
- Doesn’t use up a lot of resources
- Apps are very easy to navigate
Cons:
- No app available for iOS
OFFERS LIVE CUSTOMER SUPPORT:Bitdefender Antivirus Free is one of the more beginner-friendly free antivirus programs. Easy to navigate and with live customer support, it provides strong protection without slowing your device.
Read our full Bitdefender Antivirus review.
3. Panda Free Antivirus
Panda Free Antivirus provides cloud-based protection, which means you don’t have to store large databases of malware definitions or download updates, which can slow down low-resource devices. A near-perfect protection score in our testing and high scores from independent testing labs show that security isn’t compromised despite a lightweight design—real-time protection safeguards against various malware, including spyware.
Most free antivirus programs don’t offer many extras, and Panda Free Antivirus is no exception. The free VPN is limited to a meager 150 MB a day. There’s also a dark web scanner for checking if your email has been leaked on the dark web. It’s a shame that Panda Free Antivirus isn’t available for Mac or iOS, but if you’re on Windows or Android, there are a few better free antivirus tools for your low-resource device.
To use Panda Free Antivirus, you only need to download the app for Windows or Android.
Pros:
- Lightweight cloud-based protection
- Dark web scanner included
- Scores well for its protection
Cons:
- Windows and Android only
WORKS FROM THE CLOUD:Panda Free Antivirus operates from the cloud so low-resource devices don’t suffer in terms of performance. It includes a VPN, albeit with a very limited data allowance, and a dark web scanner. Scores well for protection.
Read our full Panda Antivirus review.
4. Avira Free Antivirus
Avira Free Antivirus is one of the few free antivirus providers that offer real-time protection. Cloud detection can quickly identify threats while allowing your device to perform to the best of its ability. This free antivirus can block spyware, adware, ransomware, and more. This is where Avira Free Antivirus excels, scoring 99.75 (out of a possible 100) in our protection testing, blocking every live malware sample we threw its way.
This antivirus is also notable for its generous selection of extras. These include a browser safety feature for blocking malicious websites, ads, and trackers. You’ll also find a password manager and VPN. The VPN has a monthly data limit of 500 MB, which makes it of little use to most. If this is your first time using an antivirus, you’ll particularly appreciate Avira’s user-friendly apps, which make it easy to see if you’re protected and when any action is required.
Avira Free Antivirus is available for desktop (Windows and Mac) and mobile (Android and iOS).
Pros:
- Real-time protection from ransomware, spyware
- Many additional features, including a password manager
- Apps are easy to use for beginners
Cons:
- Tiny VPN data allowance
REAL-TIME PROTECTION:Avira Free Antivirus stops threats from developing in real-time and receives consistently excellent protection scores from independent testing labs. Easy to use and with lots of extras, including a password manager.
Read our full Avira Antivirus review.
5. AVG Antivirus Free
AVG Antivirus Free has been recognized for its performance by both AV-Test and AV-Comparatives. This type of antivirus won’t significantly slow your device, even during full scans. AVG Antivirus Free provides multiple layers of protection from malware, and regular, real-time updates ensure it stays on top of even the latest threats.
There aren’t too many features included with AVG Antivirus Free. A Behavior Shield warns of any suspicious behavior from apps, and you even have the option to shield files from ransomware. However, there’s no ad blocker, password manager, or VPN like some other free antivirus programs already covered. Support is minimal, too, although that’s to be expected with a free antivirus.
You can use AVG Antivirus Free via its apps for Windows, Mac, Android, and iOS.
Pros:
- Protection from ransomware
- Rarely produces false positives
- Lightweight antivirus apps
Cons:
- Not many features of note
RELIABLE ANTIVIRUS:AVG Antivirus Free has consistently ranked among the best antivirus tools on the market, balancing strong protection with a lightweight design that’s ideal for low-resource devices. It doesn’t offer as many extra features as some rivals.
Read our full AVG Antivirus review.
6. Microsoft Defender Antivirus
Microsoft Defender Antivirus is the easiest option if you’re on Windows because it’s already available on your device. It had full scores for protection and performance in AV-Test’s most recent testing and has received awards in the same categories from AV-Comparatives. The fact that you don’t need to download and install it is a big plus if you’re looking for a simple but effective solution for low-resource devices.
The real-time protection from Microsoft Defender blocks threats as they occur before they can do damage to your system. As part of Microsoft Defender, you get identity theft monitoring although there aren’t too many extra features of note, at least compared to the likes of Avast One Basic. Still, Microsoft Defender offers convenience and an easy-to-navigate dashboard.
Microsoft Defender comes pre-installed on Windows 10 and 11 devices.
Pros:
- Already available on Windows devices
- Real-time protection from threats
- Includes identity theft monitoring
Cons:
- Not as many features as competitors
Microsoft Defender Antivirus is convenient:SAFE OPTION in that it’s already available on Windows. Its very strong protection from malware is complemented by identity theft monitoring. Lightweight enough that it won’t negatively impact low-resource devices.
Read our full Microsoft Defender review.
Finding the best free antivirus for low-resource devices: Our antivirus testing methodology
It’s all well and good for us to provide a list of the best free antivirus tools for low-resource devices but you’re likely wondering how we chose them. This is done through extensive testing of many different antivirus programs, most of which are ultimately not selected. It’s only those that pass our battery of tests including protection and performance that make the list.
- Lightweight performance: As part of our testing, we measure how each free antivirus consumes device resources. This involves comparing CPU and memory usage before scans (often when real-time protection is enabled) and during quick and full scans. We also measure scan durations and try to use our devices as normal during scans.
- Comprehensive protection: Most of the free antivirus programs covered in this post include real-time protection which actively detects and blocks threats before they can cause harm. Our testing process involves downloading both live malware samples to our devices to make sure that each free antivirus reliably protects you from them.
- Ease of use: Modern antivirus software should be quick and easy to download and install. Setup shouldn’t take more than a few minutes in all and you should then have access to a user-friendly dashboard with clear navigation. Automated scans and updates means you won’t have to be hands-on too often unless that’s your preference.
- Additional features: Free antivirus software doesn’t include as many features as paid versions but you can still find some valuable extras. In some cases, there’s web protection for blocking malicious downloads or links. There may even be privacy tools such as a password manager or VPN (the latter will have some sort of data limit).
- Compatibility: Most of the antivirus providers covered in this post provide apps for Windows, Mac, Android, and iOS. We’ve looked for those that are also compatible with older versions of these operating systems.
If you’d like to learn more about our process, particularly the tests we put each antivirus through, you may be interested in reading our antivirus software testing methodology.
How to use an antivirus for low-resource devices
Regardless of the free antivirus you choose, the signup and setup process will be similar. It should also be very straightforward. To make things even easier, we’ve provided some step-by-step instructions taking you from start to finish.
Here’s how to set up a free antivirus for low-resource devices:
- Choose one of the free antivirus programs for low-resource devices. We particularly recommend Avast One Basic.
- Visit the official website of the antivirus provider. Select the free version, and download it, making sure it’s compatible with your device.
- Follow the on-screen instructions to install the antivirus software.
- Open the antivirus app. You may need to log in if a free account is required to use the free version of the antivirus.
- If real-time protection is available, enable it to ensure your device is protected from threats at all times.
- Run a full scan to check for any existing threats.
- Adjust the antivirus to suit your preferences, be it scheduling scans for specific times or enabling automatic updates.
Free antivirus for low-resource devices: FAQs
Which antivirus uses the fewest resources?
All of the free antivirus programs covered in this post were chosen in part thanks to their impressive performance. We measure how each uses CPU and memory, prioritizing the more lightweight antivirus software. In terms of free antivirus tools for low-resource devices, it was Avast One that used the fewest resources. Not only this, the paid version also performed very well in testing, with only McAfee and Surfshark topping it.
Is it worth getting a paid antivirus instead?
Whether it’s worth you getting a paid antivirus instead of a free one really depends on how you use your device. If work or free time takes you to unfamiliar websites on a regular basis or if you often find yourself downloading files, a paid antivirus may be a better fit for the more comprehensive protection it provides. This is particularly the case if your device contains sensitive data such as financial information or personal identification such as Social Security numbers.
Will an antivirus slow down my low-resource device?
Many antivirus programs will slow down low-resource devices. The good news is that you’ll be able to use your devices as normal with the best free antivirus software for low-resource devices, all of which performed well in testing. You can expect them to consume minimal resources except during full scans. Even then, you can always schedule full scans for times when you’re not likely to be using the device.
