Siri's Impact on Data Usage Examined

With the release of the new Siri intelligent assistant on the iPhone 4S, some users have been curious about how much data the feature uses given that most users are on limited data plans and that Siri must communicate with outside servers in order to function. Ars Technica has now taken a look at a set of common Siri tasks, determined that those specific queries used an average of 63 KB of data.

The testing was broken down into two groups of queries, with the first being local queries requiring data only to interpret the spoken input. Data usage on those queries came in at an average of approximately 36.7 KB.

We performed six tasks that would be considered to be local tasks. These queries included things like, "Set an alarm for 3 hours from now," "Make an appointment for 2pm on Friday" (and then telling Siri to cancel the task), "Remind me to file expense reports when I get home," and "What is the contact info for Ars Technica?"

These tasks added up to a total of 220KB of data usage, or an average of 36.7KB per query. The actual numbers ranged from 60KB down to 18KB, and we believe this is correlated to the complexity of the specific query and language we used to perform it.

For more complex queries bringing results back from the Internet via Wolfram Alpha or Google, the average was 94.7 KB, with a range of 23 KB to 187 KB.

Summing up the data usage, Ars Technica calculated that a user performing all eleven of the sample queries via 3G every single day would consume approximately 20 MB of data in a month. Informal surveys of typical Siri usage revealed that even high-use customers tend to come in at about fifteen queries per day, which would represent in the neighborhood of 30 MB of data per billing cycle depending on complexity of requests.

Most carriers offer customers easy ways to check their current and historical data usage, helping them gauge how much cap space they typically have as they consider how Siri usage will affect their data needs.