For 21 years, Nickelodeon has relied on “SpongeBob SquarePants” to draw young viewers to TV. Now, the cable network wants its underwater character to lure tots and their parents to the internet.

ViacomCBS Inc., which owns Nickelodeon, is adding the entire catalog of “SpongeBob SquarePants” to its CBS All Access streaming service on Thursday, and will release “Kamp Koral,” a spinoff show, on the service early next year. “Kamp Koral” will arrive around the same time a new “SpongeBob” movie appears on All Access, making it the online home for one of the most popular kids’ franchises.

With its stock sagging and the TV business in decline, ViacomCBS is hoping kids’ programming will make All Access a must-have service for parents. In addition to “SpongeBob SquarePants,” All Access has added all past seasons of “Avatar: Last Airbender” and “Rugrats.” It faces stiff competition, however. Disney+, HBO Max, Netflix Inc. and Amazon.com Inc. are all vying for the same young viewers with fresh programing.

“We just had a sprinkling of kids, but now could be a No. 1 or No. 2 top kids brand in the country,” said Marc DeBevoise, the company’s chief digital officer.

The expansion of children’s programming is part of a larger rebranding of the service coming next year. On Thursday, ViacomCBS All Access added thousands of episodes of old shows for viewers of all ages, including “Chappelle’s Show,” “Laguna Beach” and “Love & Hip-Hop.” “Kamp Koral” is the first of many original series coming to All Access from different divisions of ViacomCBS, which also owns the BET, MTV and Comedy Central networks.

DeBevoise helped introduce All Access in 2014, making CBS the first broadcast network to create a stand-alone streaming service. All Access has delivered slow but steady growth, relying on a handful of original series like “Star Trek: Discovery” and “The Good Fight” to bring in new customers.

Rethinking TV

But investors haven’t been impressed so far with the company’s online efforts. ViacomCBS previously pitched itself as an arms dealer, licensing some of its biggest hits to rival companies. It sold “South Park” to HBO Max, and had supplied many movies from its Paramount Pictures film studio to Netflix.

The contraction of the TV business has forced ViacomCBS to increase its streaming ambitions. Its cable networks have been hemorrhaging viewers and subscribers for years, losses that have accelerated during the coronavirus pandemic. The global outbreak has also battered TV advertising. ViacomCBS stock has tumbled 40% in 2020, the most among major TV companies.

“They need to do something to accelerate the growth,” Michael Nathanson, an analyst with MoffettNathanson Research, said before Thursday’s announcement.