Which is the best voice search assistant?

John Murray

A new study has compared the performance of some of the most popular voice assistants, providing inspiration to businesses looking to leverage them for search engine optimization (SEO).

SEMrush has published its Voice Search for Local Businesses Study for 2020, the first time it has been undertaken since Google implemented its BERT technology to help the search engine understand human language.

One of the most notable aspects of the report is that Google seems to have improved its voice search performance significantly since introducing BERT. The study looked at what percentage of search queries the tool was unable to return an answer for across four Google devices, all of which performed strongly. Only 3% of queries directed to Google Home and Google Home Mini went unanswered, with Google Home Hub only slightly behind with 5%. The best Google performance was via its smartphone and tablet interface Android, where only 2% of queries could not be answered. This ties it with Apple’s equivalent Siri as the best-performing voice search assistant.

A like-for-like comparison with 2019’s results is difficult as the study was undertaken differently last year, but the report cites separate research from April 2019, which found that 35% of voice search queries could not be answered. On average, that figure is now down to just 6.3%, suggesting a highly productive year in voice search development.

You may be wondering why the figures are as high as 6.3% when Apple and Google’s voice search tools are all only unable to answer between 2% and 5% of queries. The answer is that Amazon’s Alexa is dragging the average down significantly, failing to answer almost one in four (23%) questions.

Alexa’s performance is defended with a quote from Amazon’s Dan Saunders, who notes that it is a tool designed to help people shop, rather than answer general knowledge questions, and the report surmises that Alexa is primarily a “smart speaker for homes” that responds better to voice commands than search queries.

Nonetheless, Alexa boasts 25% of the voice assistant market share, more than Microsoft’s Cortana (19%) and not far behind Siri and Google, both with 36% each. The report notes that some people use more than one assistant, explaining why these figures add up to more than 100%.

Another difference in how these devices return results is in the length of their answers. The average answer length is 23 words, but as high as 41 words for Google Home and Google Home Mini. Meanwhile, the average Alexa answer is a mere 11 words.

These mixed results indicate that different SEO tactics could be required depending on the device, but the report also quotes Google’s Gary Ilyes, who suggests that writing user-focused content will automatically optimise for voice search.

With search engines like Google becoming more intuitive and developing a better understanding of the way humans communicate, web content that appeals to humans is likely to be favoured by algorithms too. If you’re looking to improve your search engine rankings, we can help at Engage Web.