Chapter Two: Trick or Treat, Freak - S2-E2
Continuity mistake: As Hopper and El sit down to breakfast after she has surprised him as a ghost, he tells her he will bring candy home etc. When the camera is on Hopper, El is leaning on the table, but when the camera is facing her, she is leaning back.
Chapter Three: The Pollywog - S2-E3
Continuity mistake: When Dart is found in the bathroom cubicle by Will, he drops his walkie talkie when he runs away, but shortly after when his friends arrive the walkie talkie is gone.
Chapter Seven: The Bathtub - S1-E7
Continuity mistake: When Mike and Lucas notice a van pulling out of a side street and coming to them, the sky is blue, but in the next shot, it is orange. (00:04:03)
Chapter Two: Vecna's Curse - S4-E2
Continuity mistake: After Mike kisses El on the forehead, Jonathan is in the back grabbing his glasses from his pocket. In one shot, he's grabbing them out, and then the next shot has them at waist-level.
Chapter Five: The Flayed - S3-E5
Audio problem: When Joyce, Alexi and Hopper go to Murray's, Murray points a double barrel shotgun at them and it makes a sound of a pump action shotgun.
Chapter Six: E Pluribus Unum - S3-E6
Continuity mistake: When the librarian picks up the phone he picks up the one in the middle, in the next shot we see he has the one to the left and when he hangs up it's the one in the center again.
Chapter Five: The Nina Project - S4-E5
Continuity mistake: The seat belt keeps appearing and reappearing on Nancy's shoulder as she's driving.
Other mistake: When Will is in the hospital, talking about being frozen, they cut to the hallway and the lights on the suspended ceiling are 2' x 4' LED lights that didn't come out until the 2000s.
Suggested correction: There is nothing to indicate they are LED lights. They appear to be translucent panels illuminated by fluorescent lights.
Chapter Five: The Flayed - S3-E5
Continuity mistake: When Robin takes the chemical container off Erica, in the shot of Erica saying "It could be useful", Robin is holding the container upright. In the next shot, it is being held at a rotated angle, then upright in the following shot. Two shots after that, the container is suddenly rotated again, then back to upright when the shot cuts. (00:17:25)
Chapter Five: The Flayed - S3-E5
Continuity mistake: Eleven and Mike are sitting next to each other at the hospital. Eleven looks to her left in one shot and the camera changes angles. She's now looking straight ahead and immediately looks to the left again.
Chapter Seven: The Massacre at Hawkins Lab - S4-E7
Plot hole: The upside down should be mirrored, i.e. all left is right and right is left. When the team finds a gateway where Chrissy died, they should be seeing a mirror image through the ceiling. Also, all buildings should have been reversed. Directions to get there on the bike would have been confusing and reversed, and when any writing was seen in the upside down, it would have been backward.
Chapter One: Suzie, Do You Copy? - S3-E1
Continuity mistake: Steve is talking to Robin about striking out. Two girls come in and Robin encourages him to talk to them. In the first angle his shirt is lower and you can see his chest hair. Cut to the other side as he flips around to talk to the girls, and his shirt has moved up. (00:24:15)
