Playgrounds
Standalone interactive tools
Free-form, hands-on tools that go beyond the structured courses — no lesson sequence, just build and explore.
Model Builder
Assemble a small transformer from configurable self-attention and feed-forward blocks, train it live on your own text with real gradient descent, and watch a live loss curve, live sampled text, and a live attention heatmap update as it learns.
Open →Pretrained Gallery
Generate text from a real, PyTorch-trained model entirely in your browser, no setup required, or bring back your own model trained locally with the Model Builder's exported training script.
Open →Word Math
Real vector arithmetic on a real pretrained model's word embeddings, king minus man plus woman, searched against its entire real ~21,700-word vocabulary for whatever word actually lands closest.
Open →Tokenizer Playground
Compare real tokenizers side by side on your own text: character-level, BPE trained live from scratch, and WordPiece running against a real pretrained model's actual ~30,500-token vocabulary.
Open →