As with any good thing that arises, as soon as Stranger Things hit Netflix and became a massive hit, folks responded with “More please!” Fans understandably want as much Stranger Things as possible, but television is a diverse medium. You have sitcoms like The Big Bang Theory that are running for 10 seasons and counting and shows like The Walking Dead which seemingly have no endgame in sight, but you also have shows like Game of Thrones and Breaking Bad, where the creators are supremely confident in the finite nature of their stories.

So where does Stranger Things lie? Could we be spending a decade (or more) with Will Byers and Co.? It’s doubtful. Speaking with EW, creators/showrunners Ross and Matt Duffer revealed that right now they’re envisioning the show will last for just four or five seasons, but they admit those plans could change:

“Everything changes as we move forward so we’ll see,” says Ross Duffer. Adds Matt Duffer, “I want it to have a really finite ending. I don’t want it to be one of those shows that runs out of gas and they lose it because they’re losing interest. You wanna end when you’re on top.”

And while some fans may be having palpitations at the thought of only getting two more seasons of Stranger Things, I think we can all agree that it’s better to leave early and on a high note (see: Breaking Bad, The Wire, The Sopranos) rather than to overstay your welcome to the point of irrelevancy (see: Dexter, How I Met Your Mother). Wouldn’t you rather look back on Stranger Things as this great event as opposed to a show described as, “Oh yeah, the first few seasons were great but I stopped watching after X”?

Moreover, Stranger Things has never really felt like a traditional TV series. It’s more like watching a Stephen King novel unfold, or watching a really long movie. Indeed, the Duffer Brothers often referred to their Season 1 approach as writing and directing one long film, and in fact Stranger Things Season 2 isn’t called “Season 2”, it’s called “Stranger Things 2”—it’s a sequel, not a second season.

So if the Duffers are approaching this show like a film each year, it’s understandable that they’d want to cap it at a neat quadrilogy or so. They no doubt have other ideas of things they’d like to work on, and perhaps a feature-length film is one of them. There’s also the issue of the kids—they’re gonna start hitting growth spurts at different times, which will pose another issue.

As the showrunners caution nothing is set in stone yet, and producer Shawn Levy revealed last year that while developing Stranger Things 2 they had already started thinking about Stranger Things 3, so these guys aren’t going to be caught off guard. They have a plan, and it’s rolling out nicely. Just don’t expect Stranger Things to follow a meandering Walking Dead model or enter Stranger Things: The College Years.
– Source