Shares of Google parent company Alphabet dropped more than 7% in after-hours trading as advertising slowed to its lowest level in three years.

The search giant posted first-quarter revenue of $36.3 billion, up 17% from the same time last year. However, the rise was the slowest since 2016 and compared with growth of 26% for the same quarter a year earlier.

Wall Street analysts had forecasted revenue of $37.3 billion.

Much of the slowdown can be attributed to shrinking growth for Google’s ad revenue. Traditionally the service’s bread and butter, Google said paid clicks grew by 39% year-over-year, a far cry from the 66% growth at this point last year.

The slowdown comes as rivals Amazon and Facebook delivered strong revenue numbers — signaling that Google’s iron grip over online ad sales may be starting to slip.

Indeed, about 84.5% of revenue for the period came from Google’s ad business. That’s down from 85.5% a year ago.

“This ad sales deceleration was a shocker to the Street that had high hopes coming into earnings,” Wedbush Securities analyst Dan Ives told The Post. “With an A-plus earnings season so far for tech … this was a head-scratcher quarter for the bulls.”

Shares of Alphabet fell 7.2% in extended trading, to $1,202.92. It had previously closed at an all-time high of $1,296.20.

Quarterly costs rose about the same as revenue, up 16.5% from last year, to $29.7 billion.

Alphabet also saw an income boost from its stake in ride-sharing app Lyft, which went public last month.

With Reuters