Continuity mistake: Carly and Sam stick their heads in buckets of water to stay awake. Their heads and clothes are wet during the whole scene, but when the show comes back from commercial, their hair and clothes are completely dry.
Continuity mistake: Carly goes up to Sam and Freddie and puts her crumpled up napkin on her table. In the next shot, the napkin is crumbled in a different way. In the shot after that, Carly sits down and her napkin is completely flat.
Continuity mistake: Nevel gets some tapenade on his face, but the amount isn't consistent. When he looks at Spencer you can see there is more on his face.
Continuity mistake: During the attempted record-breaking webcast, when Spencer is seen explaining his sculpture on the studio's screen the red leaf blower falls backwards, but when he is seen live the blower has fallen forward.
Continuity mistake: Whenever they are doing the show, Freddy is almost always holding the large camera with blue light. When it shows him holding it, it's shaking. When it shows Carly and Sam from the angle of Freddy's cam, it is perfectly still. Always.
ISam's Mom - S4-E2
Continuity mistake: When Sam breaks into Carly's room, Carly wakes up and her hair is messy. In the next shot it is less messy and in the shot after that it is perfect. In the shots after that her hair becomes more messy.
Continuity mistake: When the iCarly gang and T-Bo rush in to set up the birthday breakfast for Carly, the balloons change positions between shots.
Continuity mistake: In some episodes, Lewbert's wart is small or not even there.
Continuity mistake: Sam fights Freddie about a bikini. When he wins he throws it down. After the fight, there is a close up of him. You can see a flag in the window of the door. Then two girls walk up. In the next close up, the flag is not there.
Continuity mistake: An unconscious Nora falls to the floor, her head landing squarely in the center of a white tile. But in the subsequent closeup, her head is on a grey tile.
Continuity mistake: Spencer arrives at his destination with butter on his elbow but it disappears a few moments later.
Continuity mistake: During Sam and Freddie's first interaction, Sam can be seen holding a coffee cup when she enters the room. For the first half of the conversation the cup is plain white, but as the camera returns to Sam, and she says, "You mean I can't play with the white balance on your super-dee duper-ee camcorder?" A green logo on the cup is plainly visible.
Continuity mistake: When Ginger Fox and her manager are in her room, Ginger squats down to tell her rabbit to roll over. Her bra strap has slipped off her shoulder. When the camera pans out, her bra strap is up. The camera zooms back in to her face, and her bra strap is down again.
Continuity mistake: In episode 3 of Season 1 we see Sam smashing the locker next to Carly's as she thinks it is hers. Gibby comes up to her and says that it's his locker and hers is the one on the right - which she promptly unlocks. However, in the next episode (ILike Jake) the start of the episode features a gag where Sam has traded lockers with Arthur Gradstein, to be next to Carly's locker as her locker is in between two sweaty aggressive football players, however in the previous episode she was seen unlocking the same locker that she apparently just traded with Arthur, after smashing Gibby's locker that is in the middle to pieces.
Continuity mistake: When the gang is at their apartment watching the news over how they think Carly pushed Shelby's grandmother down, there is a ladder outside their door that appears and disappears from shot to shot.
Continuity mistake: When Freddie holds his camera to film the web-show, he holds it at chest height pointing the camera upward to film the faces of Carly and Sam, but when you see footage from Freddie's camera it is completely straight.
IBattle Chip - S6-E6
Continuity mistake: When the table of the iCarly gang falls over due to Sam's fight with the bully, Gibby's phaser falls on the floor without a scratch. Moments later you see the phaser when the bully stands up again, all messed up.
Continuity mistake: When Carly and Sam are on the web show at the beginning, Sam puts the air hose around the edge of the watermelon. When the camera cuts back to the watermelon later on, the air hose is in the center of the watermelon.
ILike Jake - S1-E4
Continuity mistake: The locker that Sam has is introduced here, but in episode 3, she already has that locker.
Suggested correction: That's because the episodes were aired out of order, which isn't a mistake of the show. Episode 4, "ILike Jake", was the 2nd episode produced and episode 3, "IDream of Dance", was the 13th episode produced.
Continuity mistake: When Spencer first gets his Galaxy Wars thing, it doesn't show the sticker that says it is not a real prop from Galaxy Wars until Freddie tells Spencer.