The Seahawks are doing their due diligence on quarterbacks and want to talk to Kaepernick. But Seattle is not expected to sign a quarterback on Wednesday, a source told ESPN.
NFL Network was first to report Kaepernick's visit.
Seahawks coach Pete Carroll said last week that the team was exploring the possibility of adding a veteran backup like Kaepernick or Robert Griffin III.
"We're looking at everybody. We really are," Carroll said during an interview on 710 ESPN Seattle. "We've been tracking everything that's going on, and we've got cap and roster issues and stuff like that that we're still trying to manage properly. But quite frankly, yes, we are looking at all those guys."
In addition to Kaepernick, the Seahawks also hosted free-agent quarterback Austin Davis today, per a league source.
Davis spent time last season with the Denver Broncos. He hasn't played in a game since 2015 when Davis made two starts for the Cleveland Browns. He's thrown 13 touchdowns and 12 interceptions in 13 career games (10 starts).
Trevone Boykin, an undrafted free agent in 2016, served as Russell Wilson's backup last season. Wilson suffered three separate injuries but never missed a start. Boykin was arrested on misdemeanor charges of marijuana possession and public intoxication in March. He was arrested in April for possibly violating his probation because of the same incident.
Back in March, Carroll said he believed Kaepernick could still be an effective quarterback.
"We've really seen him at his best, and we've seen him be a very difficult factor to deal with," Carroll said. "The last couple of years, the offense has been changing, and they've had new coaches and all kinds of stuff.
"I don't think he's found that level that he found when he was with Jim [Harbaugh, the 49ers' former coach] that they were really on it. But it's there to be had, and I think he's a difficult guy to play against. We've always found that. We've given respect to that whenever we've had to play them."
This offseason, cornerback Richard Sherman and Bennett said they thought Kaepernick was being blackballed by NFL teams. Bennett said last week that Seattle would be "the perfect place" for Kaepernick.
Commissioner Roger Goodell was asked Tuesday at the NFL's spring meetings about Kaepernick still being unsigned.
"Each team makes individual decisions about how they can improve their team," Goodell said. "If they see an opportunity where they feel they can improve their team, I think they do it. They evaluate their players. They evaluate their systems and coaches, and they all make those individual decisions to try to improve their team," he said.
Goodell was asked if he has met with Kaepernick and said he "wouldn't be opposed to speaking to him, but I haven't."
In 12 games last season, Kaepernick completed 59.2 percent of his passes, averaged 6.8 yards per attempt and threw 16 touchdowns with four interceptions.