Bubblestand / Ripped Pants - S1-E1
Continuity mistake: In "Bubblestand" after Squidward blows the huge bubble, he tells Spongebob and Patrick that the ability to blow bubbles is in his genes. If you look at the position of the bubblestand sign, the sign is facing the direction Squidward is talking. The sign had always been facing the street, which means that Squidward was actually talking towards the street, when Spongebob and Patrick are actually to his right.
Bubblestand / Ripped Pants - S1-E1
Continuity mistake: When Spongebob first shows Patrick the technique for bubble-blowing, there are two red corals in the background - one on his right and one on his left. Later, when he shows Squidward the technique, the red coral on the left side of the screen disappears.
Bubblestand / Ripped Pants - S1-E1
Continuity mistake: In the scene where Squidward complains to Spongebob about the construction noise from his stand, Squidward's porthole in the background is black, but from the interior there is a light on (Note: this also happens in every other shot of his house.
Bubblestand / Ripped Pants - S1-E1
Continuity mistake: SpongeBob takes off his ripped pants, and throws them on the ground. His shirt sleeves are perfectly intact. Next, Sandy and Larry are shown playing volleyball. When SpongeBob is shown again, his pants are still gone, and so are his shirt sleeves.
Bubblestand / Ripped Pants - S1-E1
Continuity mistake: In "Ripped Pants", we see 3 other people at the square lifting weights besides Sandy. When Sandy lifts her weights, the crowd cheers, and we get a wide shot of the square, we see that the 3 thugs are gone.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: In "Reef Blowers," when Spongebob is flying back from the rope he is pulling, Squidward is nowhere to be seen. When the ocean is getting drained, Squidward is sitting on his porch.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: In "Help Wanted", the last time SpongeBob says "I'm ready!", his collar turns red.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: In "Tea at the Treedome", in one shot, Spongebob's pants are inflated, and in the next shot they're not.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: In "Help Wanted" Gary doesn't have eyelashes. In every other episode he does.
Suggested correction: So Gary not having eyelashes could count as an early design for him. It's common that characters and environments may undergo changes after a pilot. Not a mistake.
But Gary never had eyelashes.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: When we first see a far shot of Squidward's house, there is no potted plant on his porch. When Squidward steps out, the potted plant appears, and he rights the crooked flower. The potted plant disappears in the rest of the shots of Squidward's house.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: In "Tea At The Treedome" Patrick is seen lying on his rock, and the wooden stem thingy on his house is to the right of his house instead of the middle, and is a lot taller too.
Help Wanted / Reef Blowers / Tea at the Treedome - S1-E2
Continuity mistake: The office door in the Krusty Krab is missing throughout the episode.
Suggested correction: It's a pilot episode. Things can change with a show when it gets picked up into a series.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In Plankton! When Plankton pulls out a radio player to play his evil music on SpongeBobs pillow, it has disappeared when Spongebob wakes up. SpongeBob didn't move on it.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In Jellyfishing, when Patrick puts the net in Squidward's hand, at first it is in his left hand, but when he gets the jellyfish on the king jellyfish, it is on his right hand.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: Spongebob crashes through Squidward's house, and his bedroom is on the bottom floor. But in "Shanghied" after Squidward exits the fly of doom, you can see his bedroom is on the top floor, as it is in other episodes.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In Plankton, when SpongeBob steps on Plankton, he steps on him with his left foot, except he pulls Plankton off of his right foot.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In Jellyfishing, when SpongeBob and Patrick first take their nets to jellyfishing, they only take their own nets. But when they go to Squidward's house, they have another net, just for him.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In 'Plankton', when Spongebob is being controlled by Plankton and he bounces into the wall in the Chum Bucket, he is tumbling in a way so that when he is standing, he is facing away from the ingredient identifier. When the shot changes, Spongebob is now facing the identifier while standing.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: The words "Total Control" constantly appear and disappear from the controlling device in Spongebob's brain.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In "Plankton", when Plankton says tomorrow is his birthday, he is near Spongebob's thumb. When the camera zooms in on Plankton, he is instantly in the middle of Spongebob's hand.