Which Is the Best Voice Assistant? Here’s What We Found

It’s still far too early to declare a winner in the ever-evolving AI assistant market, but we can at least take a look at the top contenders. Google Assistant, Siri, and Alexa are currently dominating the market, but Microsoft’s Cortana and Samsung’s Bixby are making progress, as is Baidu’s Duer in China.

Their ability to recognize and respond to queries is improving steadily, and while most of the assistants are fairly limited in both what they can do and where they can live, it’s likely that future Internet of Things devices will emphasize voice controls and greatly expand the currently-limited palette of actions.

What Makes an AI assistant “The Best?”


AI assistants all have the same basic goal of listening to you and doing things for you, but each manufacturer has their own ideas about exactly how that should work. Which assistant you prefer, then, will probably depend on which of the following categories you care more about:

  • Language processing ability/finding information (Does it know what you want to know?)
  • Services/integrations (Can you take notes? Order a pizza?)
  • Smart home/Internet of Things (Can you adjust the thermostat or do the laundry?)
  • Language support (English? Chinese? Klingon?)

According to a survey by Comscore, most people use their digital assistant for asking questions, with streaming music, setting alarms, taking notes, home automation, and ordering products proving slightly less popular. For at least the foreseeable future then, voice search is probably the biggest draw.

Language Processing Ability: Who’s the Smartest?


Most digital assistants will likely converge towards the same level of linguistic competence over time as the technology improves. Some, however, have taken an early lead. Market research firm Stone Temple conducted a study by asking several digital assistants nearly five thousand questions each and rating them based on a) if the AI understood the question, and b) if the AI found a good answer to that question:

  1. Google Assistant on smartphone was the best, attempting to find nearly 80% of the questions asked and getting nearly 100% of the questions it understood correct.
  2. Cortana and Google Home both understood slightly over 60% of the questions, and they each got 85 – 90% of those questions correct.
  3. Alexa understood about 50% of queries and had an 80% success rate at finding answers when it did understand.
  4. Siri came in last among the tested assistants, understanding only 40% of questions asked and giving good answers to only 80%.

Though this test wasn’t performed on Bixby or Duer, most tests seem to indicate that Bixby, while not bad, can’t compete with Google Assistant, while Duer is still only available in Chinese, making it difficult to compare. Overall, Google Assistant definitely seems to be coming in first here, with features like “Continued Conversation” (It remembers the last few things you said so you don’t have to endlessly repeat yourself.) contributing to better natural language recognition than competitors like Alexa, which require more specifically-worded requests.

Verdict: Google Assistant

Services/Integrations: Who’s the Handiest?


Alexa has been the leader here for a while with its ever-growing bank of downloadable “Skills,” opening it up for developers to add literally thousands of useful features, from setting timers to ordering pizza.

In early 2018, though, Google Assistant introduced “Actions” (as well as bundles of actions called “Routines”) which does basically the same thing as Alexa’s Skills, and Bixby has turned out to be a great smartphone companion thanks to a growing list of integrations that help you use voice commands to control certain apps.

Siri orders pizza and makes restaurant reservations as well as any of the other apps, but with a more closed ecosystem, it may not add features as quickly. Cortana also has a growing list of skills and app integrations, but as it’s largely tied to the Windows system, it’s just not as handy to use.

As of right now, Alexa is probably still the most useful in terms of giving you access to the widest variety of functions and services, but it has some competition.

Verdict: Alexa

Smart Home/Internet of Things: Who Can Run Your Life Better?


When it comes to smart home controls, the AI doesn’t matter so much. All the AI needs to do is understand a fairly limited range of commands; it’s much more important to have a good smart home hub with plenty of integrations. There really isn’t a clear winner here: Google Home, Apple HomeKit, and Amazon Alexa all offer different experiences and connections. It really just depends on the ecosystem and design you like.

Verdict: It’s a tie

Language Support


Siri currently holds first place in terms of supported languages (over twenty), but Google plans to support over thirty by the end of 2018, which will give it the top spot. Cortana comes in eight flavors, while Alexa only supports English, German, and Japanese, which makes sense given where its markets are. Bixby comes in English, Korean, and Chinese, but will introduce four more in Bixby 2.0. Baidu’s Duer is still Chinese-only but has hinted at plans for English support at some point.

Verdict: Siri, soon to be Google

Looking ahead

Voice assistants have improved tremendously since the early days of Siri in 2011, and they’re all being relentlessly improved by the companies developing them. Google Assistant is currently ahead of the curve in terms of its language recognition technology, but once they plateau, it will only be a matter of time before the others catch up. Market research firm Ovum predicts that by 2021, Google Assistant is likely to be in the lead in terms of market share, but foresees exponential growth in Chinese voice assistants like Duer as well.

So far the trend has been for AI assistants to become more similar rather than trying to differentiate themselves, though, so the ultimate advantages between choosing one over another are likely to end up depending more on preference than technical differences.

Image credits: Alexa voice app with people chatting illustration, Artificial Intelligence & AI & Machine Learning, Stone Temple

Andrew Braun
Andrew Braun

Andrew Braun is a lifelong tech enthusiast with a wide range of interests, including travel, economics, math, data analysis, fitness, and more. He is an advocate of cryptocurrencies and other decentralized technologies, and hopes to see new generations of innovation continue to outdo each other.

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