We pitted digital assistants against each other to find the most useful AI

Alexa vs Siri vs Google Assistant vs Cortana vs Bixby.
Smart assistant apps
Which digital assistant is the smartest? Amazon

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CES 2018 demonstrated that smart digital assistants are becoming key components of a variety of gadgets. As these AI companions play more of a role in everyday life, every tech company wants an assistant app to call their own. Amazon has Alexa, Apple has Siri, Google has Google Assistant, Microsoft has Cortana, and Samsung has Bixby.

Some of these AIs can help you do everything from looking up train times to controlling a smart home—but it can be hard to keep track of which one can do what. So we downloaded all of the five major assistant apps to put them through their paces, pinpoint their differences, and decide which are the smartest and most capable.

A note before we fire up the apps: Because each of these assistants can respond to thousands of commands, it’s hard to do an exhaustive survey of their skills. Instead, we aim to give you a general flavor of what each one is like. Also bear in mind that we were talking to Alexa via an Amazon Echo speaker, so it couldn’t display text and graphics alongside its responses like the other assistants—which we tested on Android and iOS phones—did.

General questions

We started the contest by asking the assistants basic questions about topics like the weather forecast, conversions between different measurements, and trivia.

Every assistant could answer a simple query about the weather and provide the forecast for the next few days. We did notice some very slight variations in the responses, probably because these apps rely on different sources. Alexa gave the most useful information in the shortest time, which makes sense—as a voice-only program, it has to be as succinct as possible.

The apps also coped admirably with simple calculations and conversions between different units. They could even update us on the time in different time zones—though we should knock points off for Siri and Cortana, which didn’t include the day as well as the time in their spoken responses, something you need to know if a region is a day ahead of or behind you.

We also tried a number of queries that you might throw into a search engine: “How old is Barack Obama?”, “Who built the Empire State Building?”, “What is the population of France?” and “How big is California?”. All the assistants returned the correct answers, which means every one of them would make a good trivia night companion.

However, a more complex question tripped up a few of the assistants. We asked: “What’s that movie with Robert de Niro and Al Pacino in it?” In response, Google Assistant and Bixby did well, producing a list of all five films that matched the question. Siri showed just three of the films, Cortana showed the Wikipedia page for Robert de Niro, and Alexa had no idea what was going on and tried to play a video.

We upped the ante again, asking a tricky question that a human being could research in a matter of minutes: “Is NASA planning a mission to Mars?” In response, Google and Bixby provided and read aloud the Wikipedia page on a human mission to Mars, Siri and Cortana pointed us to NASA’s Journey to Mars page but didn’t read it out, and Alexa started reading out the Wikipedia entry for the Rosetta spacecraft that flew past Mars in 2007.

Evidently, these digital assistants can all return simple answers to simple searchable questions. However, they’ve still got a long way to go when it comes to more complex queries. They’ll need improved natural language recognition, and a better ability to sift through online information, before they can match a human assistant.

Organization

A good digital assistant should be able to organize your life as well as search the web. Here’s how the contenders manage your calendars, contacts, and emails.

Every one of these assistants are able to work with Google, Apple, and Microsoft calendar apps—with the exception of Cortana, which can’t access Apple calendars. When you ask, all of these apps can tell you what your next calendar appointment is and provide a list of upcoming events in response to “What am I doing next week?” Bixby and Siri do the best job of neatly displaying that information (but that’s not Alexa’s fault, as it doesn’t have a screen on a standard Amazon Echo). In addition to reviewing existing events, you can use any assistant to create new ones. However, none of the apps understood what we meant when we asked when our next free time slot or free day would occur.

As for contacts, all the assistants can act on simple “call Joe Schmo” and “text Jane Doe” commands—though with the Alexa app on your phone, you must first enable an Echo for it to be able to make calls. The functionality was largely similar across the board, with the call launching automatically on speakerphone. However, Siri also avoids accidental dials by asking you to confirm that you really want to make the call.

Of course, there are times when you want to look up contact information without necessarily calling them. So we tried to find an address for one of our contacts. Kudos to Siri and Bixby, which actually recognized a “Where does [name] live?” command. Cortana and Google Assistant returned a web result for a famous person of the same name, while Alexa wasn’t able to look up addresses.

Next, we asked all these digital assistants to show our most recent emails. Google Assistant, Bixby, and Siri all displayed the most recent messages on screen, but Alexa and Cortana couldn’t, hampered by not having tight integration with an Android or iOS operating system. Cortana could, however, send emails to specific contacts, as could Bixby, Siri, and Google Assistant. Alexa misses out again here, but expect Amazon to add this ability soon, perhaps through an update to the Alexa app that helps it work with existing email apps.

Reminders

Alarms, timers, and reminders are bread and butter tasks for digital assistants—and in this category, none of the contending apps will let you down.

All assistants could “set an alarm for 9 a.m. tomorrow.” They identified the day and time properly and even showed a confirmation on screen. A follow-up command, “cancel the alarm for tomorrow,” only worked on Bixby, Google Assistant, and Alexa. Siri didn’t understand that phrasing but did respond to “cancel alarm,” perhaps a sign that its natural language recognition lags behind the others just a little. And we couldn’t get Cortana to cancel the notification at all until we asked for a list of alarms and manually toggled it off.

As for reminders, the simple “remind me to buy milk” command met with a few different responses. Alexa asked for a day and time for the reminder before saving it, Google Assistant wanted either a time or a place when the reminder would kick in, and Bixby, Cortana, and Siri saved the note in the default reminder app without asking for any more details. If you do include a specific date and time in your original voice command, all apps will save those relevant details and time the reminder accordingly. They also understand recurring alerts like “remind me at 2 p.m. every day to exercise,” allowing you to set up daily, weekly, or monthly reminders.

In addition to times, you can also associate reminders with places. Cortana and Siri coped well with a “remind me to buy flowers when I get to London” command. Bixby and Google Assistant got halfway there—but asked us to specify a location manually rather than just accepting London from the voice command. Alexa couldn’t link a reminder to a place at all, but that’s a forgivable shortcoming considering that it lives inside a speaker rather than a GPS-enabled phone.

Finally, to avoid having the test phones buzzing for the rest of the week, we asked the digital assistants to “delete all reminders.” Alexa and Bixby obliged after asking for a general confirmation, Siri wanted us to confirm the deletion of each reminder individually, and Google Assistant and Cortana wouldn’t obey that instruction at all—we had to ask to view the reminders on the phone and then remove them manually.

Entertainment

Nobody wants life to be all work and no fun. Which is why your digital assistant must be able to update you on the news, provide sports results, and play music and movies.

In response to “What’s the news?”, Alexa reads out bulletins from a variety of local, national, and international services. The other contenders—Cortana, Google Assistant, Bixby, and Siri—display some of the day’s top headlines, as drawn from the internet, but only Cortana starts to read them aloud. However, we were testing Google Assistant on a Pixel phone, and if you have it installed in a Google Home speaker, then it can read the news to you as well.

Next, we tried asking, “What was the United score?” (referring to the English soccer team Manchester United by an abbreviation of its name). Alexa and Google Assistant answered perfectly, and Alexa even told us when the next game would happen. Siri and Cortana struggled until we specified “Manchester United” as the team name. Coming in last place in this challenge, Bixby could only provide us with a list of web results.

We found music to be a real mixed bag. It really depends on two factors: the assistant and the audio service. For example, we could call up and play Spotify playlists perfectly with Alexa, Google Assistant, and Cortana. But when we tried other music apps like Apple Music and Google Play Music, the assistants fell short. As for Siri, it could only control Apple Music, and Bixby was even more limited—it was only able to play audio files stored on the phone.

Similarly, movies varied from app to app. Alexa can open up apps and play specific films when you say “show me an action movie” or “open Netflix“—as long as you’ve connected it to a Fire TV on the same wireless network. Google Assistant, Siri, and Bixby pull up those videos, and any YouTube clips, on the phone you’re using. In addition, Siri can fire up anything you’ve stored in your iTunes library and Google Assistant can beam any video content to a nearby Chromecast. We’ve left out Cortana, because it doesn’t possess the same video-playing talents that its competitors do, although it can bring up a few YouTube videos via a Bing search.

Although this is the current state of entertainment on assistant apps, it could change very quickly, because Google, Samsung, Microsoft, Amazon, and Apple are constantly making new partnerships. For example, when it comes to displaying news, the assistants rely on receiving compatible content from news producers. Once those partnerships exist, the companies can update their apps to add additional features.

Final verdict

This might seem like a lot of testing, but these assistants also have many features we haven’t explored, which is a testament to how capable they’re becoming. Still, with our basic review, we managed to rank these digital pals in different ways.

In our opinion, Google Assistant is the best at recognizing natural language and responding to follow-up questions. This is to be expected, as the app can draw on Google’s hefty experience in search and AI. It also has the advantage of tight integration with other Google services, such as Android, Gmail, and Google Maps (the latter lets it quickly launch turn-by-turn directions).

Siri possesses a similarly tight integration with smartphones, but only of the iOS variety. However, its lack of support for non-Apple apps and services occasionally lets this assistant down. If you prefer iPhones, though, there’s no reason to switch: Siri will work great with Apple’s Mail, Calendar, Contacts, and Maps apps.

Where Alexa really excels is in the number of third-party skills, from companies like Domino’s and Uber, and outside apps, such as iCloud and Spotify, that you can plug into the service. It can also recognize natural language patterns well. On the downside, it’s not available as a phone app, but Amazon is fixing that drawback as we speak, so it won’t count as a disadvantage for much longer.

Cortana, the Microsoft assistant hitching a ride on Android and iOS, seems the most disjointed of the digital assistants we tested. That said, it syncs neatly with Windows 10, works across multiple devices, and does make some effort to learn the news stories, sports scores, and other interests you follow. Unfortunately, it doesn’t have quite the same polish as Google Assistant, Siri, or Alexa.

Finally, as the newest of these apps, Bixby is still a work in progress. At the moment, it can’t offer as many features as its rivals do. However, it does control Samsung devices well (try commands like “close all recent apps”) and works nicely with the manufacturer’s own mobile apps. Expect some big improvements to come.

 

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