Landing Richardson solidifies the interior of Seattle's defensive line and quells some of the concerns raised by the uncertainty surrounding rookie second-round draft pick Malik McDowell, who was injured in a July ATV accident.
The Seahawks will be counting on the likes of Williams to emerge and players such as Paul Richardson and Tyler Lockett to stay healthy - say what you want about Kearse's inconsistency catching the ball but he missed just two games in five years due to injuries.
For Kearse, it marks the end of an era, as the Lakewood native will continue his playing career somewhere else than the Pacific Northwest.More news: Super Eagles offer support to ill Carl Ikeme
Richardson, 26, is one of the best young defensive linemen in the National Football League and earned a spot in the Pro Bowl in 2014, but he struggled to stay out of trouble in the early years of his career.
ESPN's Adam Schefter was first to report the deal.
Kearse was on the outs in Seattle, but now goes to a NY team devoid of WR help.More news: LG V30 is waterproof with an IP68 rating
Adding Jermaine Kearse upgrades an very bad and inexperienced New York Jets recovering core that has been reeling from losing number one receiver Quincy Enuwa for the season. He's coming off a bit of a down year, with 62 tackles but only 1.5 sacks.
Kearse signed a $13.5 million, three-year deal with the Seahawks before the 2016 season but became expendable because of Seattle's depth at wide receiver.
He could be a starter in Seattle's base packages depending on what happens with Ahtyba Rubin, who may be traded, but Richardson's presence in Seattle's nickel pass-rush will make that foursome arguably the NFL's best.
In his sixth season out of Washington, Kearse has 153 receptions, 2,110 yards and 11 touchdowns in 69 career regular season games, all with the Seahawks.More news: Body of Missing Pregnant Woman Discovered Wrapped in Plastic in River
The Jets ended up choosing Wilkerson to re-sign, and Williams has three years remaining on his contract. Among the players released this offseason were veteran center Nick Mangold, receivers Brandon Marshall and Eric Decker, linebacker David Harris and cornerback Darrelle Revis.