AI Face-Off: Siri vs. Cortana vs. Google Assistant vs. Alexa

Accessibility and trends

Accessibility refers to the number of devices that host the virtual assistant. Here’s how the various AI assistants compare in this category, listed from the most accessible to the least accessible.

Google Assistant

Google Assistant is available on all Android and iOS devices, as well as on Chromebooks. Google has its own line of Google Home speakers, including the Google Home Mini ($49) and Google Nest Audio ($99.99), all of which are built for use with Google Assistant. Google also makes it easy to search via third-party Google AI-enabled speakers, like the Harman JBL Link Music ($119.95), Bang & Olufsen BeoSound 2 ($3,199) and Solis SO-2000 ($149.99). The fact that so many major players in the speaker and headphones space are releasing Google AI-enabled hardware at varying prices speaks volumes as to who is coming out ahead in the AI-assistant space. [Check out the best Android apps for efficient workday planning.]

Alexa

Amazon’s smart assistant, Alexa, is accessible through the Amazon Echo line of speakers, Fire tablets and Fire TV. Of all the AI assistants we studied, Alexa may have the biggest advantage for business use, since it’s available on the widest variety of device designs. Although Google’s AI assistant can be found on plenty of speakers, they all look similar. Amazon, in contrast, sells dozens of Alexa-enabled designs, including speakers of all sizes and modern-looking speakers with glossy touchscreens.

There are also some third-party smart speakers and other devices that support Alexa, including the Sonos One wireless speaker ($2,199.99) and the Altec Lansing VersA Smart Portable speakers ($86.10). There is an Alexa app as well, but it’s intended primarily as a supplement to another Alexa device and not as a stand-alone AI assistant. 

Siri

You can access Siri on nearly any Apple device, including MacBooks, iPhones, iPads and Apple Watches. Apple also sells its own speakers, called the HomePod ($299) and the HomePod mini ($99). Using Siri with a third-party device is possible, but it requires a HomePod mini to connect to your non-Apple device. According to Apple, this is to protect customer privacy so third-party devices can’t access your voice-based commands. [Do free AI tools pose a security risk to your small business?]

Cortana

Microsoft’s AI assistant, Cortana, was launched in 2014 and was previously included on Windows machines. However, this AI assistant is no longer supported on Android and iOS devices. Microsoft also announced that Cortana would be retired from Windows in late 2023. Cortana won’t be going away entirely, though, as it will remain a standard integration in Microsoft Office products, such as Outlook and Microsoft Teams. Of course, this means Cortana is much less accessible than the other options on this list.

Ease of setup

The ease of setup refers to how long it takes to get the assistant up and running, as well as how simple that process is. All of the AI assistants we evaluated have options to customize the personal-assistant experience, including app integration, unique settings and adaptive responses.

To maintain an even testing ground, we did not consider additional setup steps that fall under the category of customization; we considered only how long it takes a new user to turn on the device and start asking questions. Google Assistant, Siri and Alexa all required virtually no setup time (you just sign in to a network and start) and were completely intuitive. None of these took more than about 45 seconds for initial access, and that included turning on the device or, in Alexa’s case, plugging it in.

Cortana was a different story. The user experience of attempting to log in to the Cortana app on a supported device took quite a bit of troubleshooting. Cortana’s integration will be automatic in Microsoft Office products going forward, so it remains to be seen if these issues will persist.

Voice recognition

For voice recognition, all we wanted to know was how often the virtual assistant could recognize the words we said. We didn’t consider context or the value of the responses given, just basic recognition. We also tested voice recognition at various distances from the devices, with varying levels of background noise.

Google and Siri understood us well when the room was quiet and we were close to the devices. There were a couple of funny misunderstandings, like when we asked Siri, “What’s the date four weeks from now?” and it gave the date for one week later because it thought we said, “What’s the date for a week from now?” All in all, though, the voice recognition was impressive under ideal conditions.

However, when we used Google and Siri to do anything sound-related, like read a news article or play music, the assistants couldn’t hear us when we spoke at a normal volume. When we shouted, Google eventually responded, but Siri did not. We also had to manually turn off the sound on the iPhone to get Siri to stop playing the news, which defeats the hands-free purpose.

Alexa’s voice recognition was spotty. Like Google and Siri, it could not understand us at all when there was even soft music playing, and we had to manually shut down the speaker to get it to stop playing music. Unlike the other two assistants, Alexa had issues understanding basic questions, except our voice commands, even when the room was silent.

One of the test questions included repeatedly asking for help getting plane tickets, and each time, Alexa thought the request was for movie tickets and directed us to Fandango. When we  asked for future dates (“What’s the date for a week from now?”), it simply replied, “Sorry, I don’t know that,” while other assistants had no trouble understanding identically phrased questions.

In our testing, Cortana performed the worst by far in basic voice recognition. Microsoft’s assistant had issues understanding us even with zero noise interference. Below are just a few examples of basic inquiries Cortana could not understand, even when stated slowly and clearly with no background noise.

• “Cancel this task.”
• “I want to set a reminder.”
• “Does Amazon sell printer paper?”
• “I need help finding a restaurant.”
• “Do I have any reminders coming up?”

The other three assistants could understand all of these inquiries. And Cortana understood at least some of the other inquiries we made (like those about the weather), so it wasn’t a microphone issue.

Success of queries and ability to understand context

The value of an AI assistant lies in its ability to understand natural language and context and deliver a useful response. To test this skill, we devised questions with context-reliant follow-ups. Here are a few questions we asked each assistant:

• “How much is $5 in euros? What about in yen?”
• “Where is there an Applebee’s near me? Can you make a reservation?”
• “How long will it take me to get to LaGuardia Airport in the car? How about by subway?”

We also asked each assistant a list of common questions about scheduling, setting reminders, shopping online, booking business travel accommodations and getting directions. Below, we’ll discuss how the products fared, from worst to best.

Cortana

Unfortunately, Cortana effectively removed itself from the running here because it couldn’t even hear or understand us on a basic level. When Cortana did understand us, it did not respond helpfully or intuitively. For example, when asked for directions to the nearest airport, it searched for nearly a full minute and then returned with a list of results from Bing, which mostly linked to general airline ticket websites such as Expedia.

When asked to convert from U.S. dollars to yen, which all of the other assistants did with ease, Cortana did not reply aloud but rather brought up a page from Bing with a list of general responses about currency exchange from Answers.com. Whenever we asked follow-up questions, especially those dependent on context, Cortana either didn’t respond at all, said it didn’t know or directed us to allow permissions from a third-party app.

Alexa

Alexa worked well when answering basic questions, especially those that pertained to purchasing items on Amazon and setting reminders. However, when we got to more complicated questions that required context or close attention to detail, Alexa faltered. We  made multiple attempts to get Alexa to help purchase airline tickets, but the assistant consistently referred us to Fandango to buy movie tickets. It rarely answered follow-up questions, and when it did, it was often with a polite but unhelpful “Sorry, I don’t know that.”

In general, Alexa could do part of each task asked of it. For example, it could say where the closest Applebee’s was, but it couldn’t make a reservation. It could tell us how much $5 was in euros, but when we followed up with “What about yen?” it didn’t know. When asked how long it would take to get to LaGuardia Airport, it said, “As I don’t know your speed, I can’t tell you how long that will take.”

Alexa seems to rely on very specific terminology for commands. For example, when asked to read the news, it did. But we couldn’t get it to stop, even after trying multiple direct commands, like “stop” and “turn volume off.” The only phrase that eventually worked (which we had to look up online) was “stop flash briefing,” which isn’t exactly intuitive. It was easy to set up reminders with Alexa, but when each reminder time came, Alexa would just blare an alarm with no indication of what the alarm was for, and we had to turn off the alarm manually.

Alexa is an OK tool for ordering on Amazon, and it may be good for smart-house integration. However, it’s not the best AI for natural language use; anyone who adopts Alexa as an AI assistant should peruse user guides before setting it up and understand its limitations. [Learn about Alexa for Business.]

Google Assistant vs. Siri

It’s worthwhile to compare Google Assistant’s and Siri’s abilities to understand context and intuitive speech, because these two options are neck and neck in ease of use and intelligence.

When asked for directions to One World Trade Center, both Google Assistant and Siri responded with clear driving instructions. When we added a follow-up question about public transportation directions, Google Assistant responded verbally with directions to and from the subway, as well as gave an automatic link to step-by-step instructions in Google Maps. Unfortunately, Siri simply responded with alternate driving directions. No matter how we asked, Siri would not give public transit directions.

However, Siri bested Google Assistant in tasks such as finding specific restaurants and making reservations. In fact, Siri was the only assistant that could not only find a nearby restaurant (which Google Assistant did, too) but also place a reservation. When we asked Google Assistant to find a specific restaurant, it did. But when asked to book a reservation, it inexplicably took us to DisneyWorld.com. We tried several times to book a reservation through Google Assistant, with no success. 

The ability to make hands-free restaurant reservations with Siri could be useful. However, Apple’s assistant falls short if your requests are not specific. For example, when we simply said, “I need help finding a restaurant,” Siri responded with a list of Google results that were literally instructions on how to find a restaurant, while Google Assistant read between the lines and showed us restaurants nearby.

Google Assistant was also better than Siri for travel information, but it still wasn’t perfect on follow-through. When we asked Siri for flights from New York to Paris, it just Googled the  question and showed us the responses. When Google Assistant was asked for flights from New York to Paris, it asked for dates and started pulling up available reservations. But when we tried to book the flights, it simply said, “No problem!” and then did nothing. One cool thing Google Assistant offered, without prompting, was to email us if prices changed on the flights we were interested in.

When we asked the assistants to read the news, Google Assistant immediately started playing a recent NPR podcast, while Siri Googled several news sources. We noticed throughout many different tasks that Siri rarely responded aloud, while Google Assistant nearly always did. While this is likely a matter of playing with a few settings, it’s an interesting difference to note.

AI assistants have a lot to offer, but they have a long way to go

No AI assistant we tested was perfect. This is still young technology, and it has a long way to go. There were a handful of questions that none of the virtual assistants could answer. For example, when asked for directions to the closest airport, even the two best assistants on our list, Google Assistant and Siri, failed hilariously. Google Assistant directed us to a travel agency, while Siri sent us to a seaplane base.

Still, judging purely on out-of-the-box functionality, Siri and Google Assistant are our top choices. We recommend making your final decision based on your hardware preferences. None of the assistants are good enough to go out of your way to adopt hardware you’re not comfortable with. Choose between Siri and Google Assistant based on convenience and the hardware you already have.

Natalie Hamingson contributed to this article.