How many computers, smartphones, and tablets do you have in your house? If the answer is more than two or three, and if they’re running a variety of platforms, you’re a good candidate for a cross-platform multi-device security suite. As long as your devices run Windows, Mac OS, or Android, ESET Multi-Device Security 9 may suit your needs. However, a little digging suggests that you’ll probably do better with one of the competing services.

Comparative PricingPricing for this multi-device security suite is a little different from most. An $84.99-per-year subscription gets you six licenses, $99.99 gets you 10 licenses, and both deals are half-price at this writing. However, your licenses aren’t completely interchangeable. In both deals, half the licenses are good for Windows/Mac, the other half for Android. iPhone users are out of luck.

For $89.99 per year, you could get a McAfee LiveSafe (2016) subscription that protects all of the devices in your household, and it supports Windows, Mac OS, Android, iOS, and even BlackBerry. It’s worth noting that as of the latest update, all of the products in the McAfee product line include unlimited multi-device support.

Symantec Norton Security Deluxe costs $69.99 per year and protects up to five Windows, Mac OS, or Android devices. At $89.99 per year for 10 devices, Symantec Norton Security Premium is a better deal, and it also includes 25GB of hosted online backup.

Kaspersky Total Security (2016) is a bit pricier, at $89.95 for three devices, $99.95 for five, and $149.95 per year for 10 devices running Windows, Mac OS, iOS, or Android. My own testing suggests that this product is at its best protecting PCs and that its iOS support is seriously limited.

Kaspersky, McAfee, and Norton all let you allocate your licenses any way you like, with no restriction to use some for one platform, some for another. Unless your collection of devices happens to be evenly divided between Mac/Windows and Android, choosing ESET means you’ll wind up with some spare licenses that you can’t use.

Getting StartedIf you purchase this product online, you get an email explaining how to get started. Those who buy a CD can follow instructions on the box. From the email message, it’s simple enough on a Windows or Mac device. Choose the ESET product you want to download, install it, and activate it using the supplied key. As you’ll see below, those using Windows and Mac devices can choose between two different security products.

During the course of installation on a Windows or Android device, you’ll be prompted to activate ESET Anti-Theft. Sorry, Mac users; you’ll just have to rely on Apple’s iCloud Find My Mac feature. Anti-Theft activation requires that you create an ESET account, and gives you access to the ESET online portal. I’ll cover the portal later; for now, let’s look at what’s available on the different platforms.

Protection for Windows DevicesYour ESET subscription lets you install either the standalone ESET NOD32 Antivirus 9 or the full ESET Smart Security 9 suite. Since the suite includes everything found in the antivirus and more, most users will choose it. Please read my review of ESET Smart Security for full details on the suite’s features. I will briefly summarize here.

ESET’s antivirus gets mostly excellent ratings from the independent labs. It didn’t fare as well in our own hands-on malware blocking test, but it scored very well in our tests that evaluate protection against malicious URLs and fraudulent (phishing) websites.

The antispam component proved quite effective. It did its job without slowing the process of downloading email, completely avoided throwing valid mail into the spam oubliette, and let just a little over 6 percent of spam into the Inbox.

ESET’s firewall component handles blocking outside attacks, but its program control side is rudimentary. By default, it just allows all outbound access and blocks any inbound access not permitted by rules. If you enable full program control by setting the firewall to interactive mode, it buffets you with popup queries for all programs attempting Internet access, including your browsers and built-in Windows components.

Parental control is limited to content filtering. While the content filter wasn’t fazed by off-brand browsers or secure anonymizing proxy websites, it did spend a lot of time blocking Web analytics and other innocuous URLs. In testing, I found that Google image searches, whether naughty or nice, displayed five or more unfiltered images and failed to display any after that first group, stacking up hundreds and even thousands of parental control warning messages.

The suite includes several unusual features, of varying utility. Similar to Kaspersky’s Safe Money and Bitdefender Internet Security 2016’s SafePay, ESET’s Banking and Payment Protection feature offers to open financial sites in a hardened browser that’s isolated against interference by other processes. The anti-theft feature lets you get the location of a lost or missing PC, gather screenshots and webcam photos, and even send a message to the finder of a lost device. In testing, it proved very slow to respond. Finally, the Device Control system lets you limit access to specific devices or device types for specific users or groups. This last feature will see use in business settings, but probably not at home.

Protection for Mac OS DevicesAs with Windows, ESET gives Mac OS users a choice of two protection products, ESET Cyber Security and ESET Cyber Security Pro. A single license for the basic Cyber Security would cost $39.99 per year; for the Pro edition, $59.99 per year. Neither product gives users the same level of security as ESET Smart Security for Windows.

ESET Cyber Security includes antivirus protection, with on-demand, on-access, and scheduled scanning. You can choose a quick scan that looks in the most likely hiding places, or a deep scan that combs every nook and cranny of your Mac. ESET also scans incoming email for malware. And it checks for Windows and Linux threats, too, so your Mac doesn’t become a conduit for malware to attack other devices on the network.

I didn’t test the Mac version’s phishing protection separately, but if it’s equivalent to what you get with a Windows installation, it’s quite effective. In Windows testing, ESET came closer than many competitors to Norton’s detection rate, and did significantly better than the protection built into Chrome, Firefox, and Internet Explorer.

Those who opt for the Pro edition (and who wouldn’t?) also get simple firewall protection that lets you control data connections both on the local network and the Internet. Firewall protection specifically aims at fending off Wi-Fi attackers.

Parental control is also only available in the Pro edition. It’s not quite the same as what’s in the Windows edition, though it’s also limited to content filtering. Instead of year-by-year age-based profiles, the Mac edition offers more general profiles such as Child and Teenager. And instead of almost uncountable categories organized by group and age, the Mac edition offers to block 27 specific categories.

A number of features from the Windows edition aren’t found on a Mac installation. As noted, anti-theft is only for Windows and Android. The Mac version doesn’t include spam filtering. Banking protection and Device Control are also missing in action on the Mac. To be fair, few security vendors offer the same level of protection for Macs as they do for Windows boxes.

Android ProtectionOur review of ESET Mobile Security & Antivirus (for Android) is a little dated, but things haven’t changed too much. The biggest change I see is that you can now control anti-theft via the Web console as well as through coded SMS messages. We’ll update that review when possible.

I found getting ESET installed on my Nexus 9 test device to be a bit awkward. I started by clicking on the Android link in the registration email and launching the resulting APK. Of course, the Nexus refused, warning me that installing apps from unknown sources is dangerous. So I downloaded from the Google Play store…and found that my not-for-sale special activation key wasn’t accepted. Luckily consumers won’t encounter that second problem.

Installing Norton on an Android device is certainly simpler. With Norton, your activation key is baked right into the download link. McAfee can scan your network to find unprotected devices and, for all device types except iOS, it automates linking that new installation with your existing account.

With the Android app installed and activated, there are still a few more configuration steps. You must enable anti-theft, create a lock/unlock password, and set ESET as a device administrator; the app walks you through necessary steps. You may need to optimize the device for anti-theft, just like in the Windows edition. For example, if you don’t have a strong screen lock (pattern, PIN, facial) you’ll have to create one.

Anti-theft works in much the same way as under Windows. You can click a button to test the feature, which gets you the current location and snaps photos using both front and back cameras. When you report the device as actually missing, ESET locks it and starts monitoring its location, as well as sending you screenshots and camera photos.

Of course, your device might have been found by a nice person who only wants to help you get it back. You can send a message that will show up on the lock screen. The finder can also tap Contact owner to see your email address. If you find the device yourself, you can unlock it by entering the unlock password you created during installation.

Most mobile anti-theft products let you invoke four actions: locate, lock, wipe, and scream. Locate and lock are automatic when you report an ESET-protected device as missing. Once the device is locked, you can wipe it remotely using the online console. Scroll down to find the button that lets you trigger a siren, to help find the device when it’s nearby.

When you install ESET on an Android smartphone, you get another set of choices for controlling the anti-theft system. You can send password-protected SMS messages to lock, wipe, or locate the device, or to trigger a loud siren. In addition it can notify a pre-selected trusted friend if your phone’s SIM card is removed. Because my Android test device is a tablet, I couldn’t directly experience these features, nor the SMS and call blocking features. In any case, SMS blocking only works on Android versions before 4.4.

Naturally ESET includes antivirus protection for your Android. You can invoke a Smart, Quick, or Deep scan at any time, and the real-time protection checks new apps for malware. The anti-phishing page clearly identifies the browsers it supports, which is handy.

The Security Audit component has two parts. Device Monitoring checks for security problems on the device itself. For example, it warned that my device was set to allow installs from unknown sources, which I knew, since I had to change that setting to install ESET. But it also warned that USB Debugging was turned on. How did that happen? I turned it off right away.

The other part, Application Audit, reports on all apps that have certain potentially risky permissions. For example, it lists all apps that can access your contacts, track your location, or use for-pay services. My clean test device was pleasantly free of such apps.

Online ConsoleI’ve mentioned that you can manage the anti-theft feature from ESET’s online console. At first glance, you might think there’s a lot more you can do, as the anti-theft tab is sandwiched between two other tabs labeled Parental Control and Social Media Scanner. However, things aren’t quite as they seem.

ESET Parental Control for Android is a separate product that lists for $29.99 per year. That subscription does get you protection for any number of Android devices, but it’s not part of ESET Multi-Device Security.

As for the Social Media Scanner, there’s a bit of a story here. ESET used to offer a Facebook malware scanning app, but that functionality is now built into Facebook itself. You can install ESET’s Twitter app to watch for dangerous links in your feed, but here again, this is not actually part of the Multi-Device Security product.

Some similar services let you manage your subscription through an online console. As noted, Norton lets you see how many licenses you have left, and helps you use those licenses on new devices. McAfee searches your network for devices that don’t yet have protection. ESET’s console doesn’t include this kind of license management.

Look ElsewhereA subscription to ESET Multi-Device Security 9 does let you protect your Windows, Mac, and Android devices, but with some limitations. If you go for six licenses, you can use three on Windows/Mac and three on Android. A 10-license subscription protects five Windows/Mac devices and five Android. Few competing products impose this kind of restriction on the use of your licenses.

Symantec Norton Security Deluxe protects 10 devices including any mix of Windows, Mac, and Android, for a lower price than ESET, and with 25GB of hosted online backup as a bonus. For the same price, McAfee LiveSafe protects absolutely all of your Windows, Mac, Android, iOS, and BlackBerry devices. And the central Windows security suite in both of these products outscores ESET’s equivalent. If you need cross-platform multi-device security, look to Norton or McAfee, our Editors’ Choice products in this area.