Tokenizer Mono font visualizes LLM token boundaries

A developer created Tokenizer Mono, an OpenType font family that uses advanced font substitution rules and color tables to visualize how various large language model tokenizers split text as you type. By mapping different font faces to specific tokenizers like OpenAI's and Meta's, the font highlights token boundaries and token types entirely through typography without running external scripts. Testing shows the font achieves high boundary agreement with real tokenizers despite operating significantly slower than native programmatic tokenization. Open article →