Goofs

In the bathroom, when he's washing his eye, he has a Subconjunctival hemorrhage in his left eye, in his next scene, his eyes are perfectly clear.

When the family were escaping from the attic window the ladder propped against the sloping roof change type between shots.

At first it was a traditional wooden ladder viewed from the window but then it changed to a wider aluminium ladder as the family made their escape.

When Paddy recommends to Louise that cold water therapy could help her neck condition, they all go to the rock, and start to undress. Paddy takes off both socks, and in the next cut, he takes his right sock off again.

At about 1hr 24 mins, when Louise takes the box cutter out of her pocket, it's red. When she drops it seconds later, it's blue.

On their first attempt to drive away, they come back for the doll. The adults leave the daughter in the car and tell her to stay there, but 2 minutes later she appears in the house with the doll found, they never show her coming into the house at all or any acknowledgment that she did not stay in the car.

The relax app that's used to calm Agnes' anxiety has an animated rabbit doing inhale/exhale exercises, and the instructional text incorrectly says, "Breath In, Breath Out" instead of, "Breathe In, Breathe Out".

Mackenzie Davis is supposed to be American, but she talks like a British expat.

At about 56 mins, Paddy pours Louise a glass of wine, but she picks it up and starts drinking while the pouring is still audible.

At the start of the movie, the antagonists are met in Italy. However it would be highly unlikely that they would have been able to travel with their "son", since they couldn't use his original passport and couldn't get a new one for him. UK - Italy travel requires a border check.

After being attacked with sulfuric acid, Paddy pours water over it. This action would instantly boil the solution, causing potentially deadly injuries.