Sorting the books into a timeline can be messy, but I like to break them into separate lanes so they stop feeling contradictory. The three-book set — 'The Silver Eyes', 'The Twisted Ones', and 'The Fourth Closet' — absolutely follow a single, continuous storyline. Read them in that order and the characters, mysteries, and revelations flow directly from one book to the next; it’s essentially a straight trilogy with a beginning, middle, and end.
Beyond that trilogy, things split. The 'Fazbear Frights' series and the later 'Tales from the Pizzaplex' collections are short-story anthologies. Most stories stand alone, but there are recurring motifs and occasional characters or hints that connect some tales. Those connections form small threads rather than a single sweeping timeline, so you can enjoy them individually or hunt for the easter-egg links.
Then there are graphic novels and companion books like 'The Freddy Files', which reinterpret or explain things rather than slot into the trilogy’s timeline. In short: yes, some books share a single timeline (the trilogy), but the whole library of 'Five Nights at Freddy's' books is more like multiple timelines and parallel stories that riff on the same mythos. I find that fractured approach keeps things spooky and surprising, which I secretly love.