April 25 (Reuters) - Roku beat Wall Street estimates for quarterly revenue and forecast second-quarter sales above estimates on Thursday, buoyed by strong ad sales and the ongoing shift to streaming from cable TV .

Shares of the company jumped 7.5% in trading after the bell.

Roku, which sells streaming devices and has its own free, ad-supported channel, has seen more people turn to its platform as major streamers such as Netflix increased prices and economic uncertainty pressured consumer spending.

A shift towards subscription-based streaming services from traditional cable packages and the launch of third-party streaming channels, including Peacock, Disney+ and HBO Max, on Roku has also fueled user growth.

The company posted net revenue of about $882 million in the first quarter, compared with analysts' average estimate of $848.6 million, according to LSEG data.

Roku forecast second-quarter revenue of $935 million, above analyst estimates of $931.4 million.

(Reporting by Juby Babu in Mexico City; Editing by Shilpi Majumdar)