midPyTorch
What is the difference between model.train() and model.eval()?
Updated May 17, 2026
Short answer
train() enables training behavior; eval() switches to inference mode.
Deep explanation
Layers like dropout and batchnorm behave differently depending on mode.
Real-world example
Used when switching between training and validation loops.
Common mistakes
- Forgetting eval() during inference.
Follow-up questions
- Does eval() disable gradients?
- What changes in BatchNorm during eval?