TransformerLens vs NNsight, according to AI

“If your goal is debugging and visualizing the internal computations of a production Transformer, my top pick is TransformerLens—with NNsight as the stronger choice when you need to instrument an arbitrary Hugging Face/PyTorch production model.”

“If you mean debugging the actual internals of a Transformer in production—activations, attention, residual streams, causal interventions, and tracing—the best choice today is NNsight.”