– Facebook plans to announce Thursday a substantial redesign of its News Feed — a makeover aimed both at keeping users glued to the social network and luring more advertising dollars. Company executives have broadly said they want to make the News Feed, the first page every user sees upon logging in, more relevant.

In an earnings call with Wall Street analysts in January, the company’s founder and chief executive, Mark Zuckerberg, offered some hints of what a reimagined News Feed might look like: bigger photos, more videos and “more engaging ads.”

“Advertisers want really rich things like big pictures or videos, and we haven’t provided those things historically,” Zuckerberg said at the time.

Facebook declined to comment on the redesign, which is scheduled to be announced at its headquarters in Menlo Park, Calif. But the adjustments will reflect the tricky balance that Facebook faces now that it is a public company: to keep drawing users to the site while not alienating them with more finely targeted advertisements, which is Facebook’s chief source of revenue.

The pressures are acute, given Facebook’s still anemic performance on Wall Street. The stock came out of the box in May with a valuation of $38 a share, slumped to half of that last fall, and has remained for the most part under $30.