Dec 2025 - Rolling Release
Gemma Scope 2
Google DeepMind, Language Model Interpretability Team
August 2025
The Circuit Analysis
Research Landscape
Anthropic, EleutherAI, Goodfire AI, Google DeepMind
Explore, steer, and experiment on AI models.
Explore
Browse over four terabytes of activations, explanations, and metadata.
Neuronpedia supports probes,
latents/features, custom vectors,
concepts, and more.
Releases
Models
Jump To
Graph
Visualize and trace the internal reasoning steps of a model with custom prompts, pioneered by Anthropic
'
s
papers.
Steer
Modify model behavior by steering its activations using latents or custom vectors. Steering supports instruct (chat) and reasoning models, and has fully customizable temperature, strength, seed, etc.
Search
Search over 50,000,000 latents/vectors, either by semantic similarity to explanation text, or by running custom text via inference through a model to find top matches.
Search via Inference
API + Libraries
Neuronpedia hosts the
world's first interpretability API (March 2024)
- and all functionality is available by API or Python/TypeScript libraries. Most endpoints have an OpenAPI spec and interactive docs.
Inspect
Go in depth on each probe/latent/feature with top activations, top logits, activation density, and live inference testing. All dashboards have unique links, can be compiled into sharable lists, and supports IFrame embedding, as demonstrated here.
Who We Are
Neuronpedia was created by
Johnny Lin, an ex-Apple engineer who previously founded a privacy startup. Neuronpedia is supported by Decode Research, Open Philanthropy, the Long Term Future Fund, AISTOF, Anthropic, Manifund, and others.
Citation
@misc{neuronpedia,
title = {Neuronpedia: Interactive Reference and Tooling for Analyzing Neural Networks},
year = {2023},
note = {Software available from neuronpedia.org},
url = {https://www.neuronpedia.org},
author = {Lin, Johnny}
}