niieani/gpt-tokenizer

When you send text to an AI like GPT-4, it doesn't read your words the way humans do. It breaks them down into smaller pieces called "tokens." The gpt-tokenizer project is a tool that lets JavaScript applications do this exact same translation. It lets you count how many tokens a piece of text will use, predict what a chat will cost before you send it to OpenAI, and translate the AI's token-based responses back into readable text. At its core, the library translates human text into a sequence of numbers using the same method OpenAI uses internally. Beyond simple translation, it offers practical helpers for real-world applications. You can check if a prompt exceeds a model's token limit without processing the whole text, estimate API costs based on token counts, and handle streaming data as it arrives in chunks. This library is useful for anyone building applications on top of OpenAI's APIs. If you are building a customer support chatbot, you could use it to ensure a long conversation history doesn't exceed your model's token limit before sending it. A startup building an AI writing tool could use the cost estimation feature to show users how much a specific prompt will cost before they generate it. It is already used in production by well-known companies like Microsoft and Elastic. A notable aspect of the project is its speed and flexibility. The creators emphasize that it is the fastest tokenizer available for JavaScript environments and can run synchronously, meaning it doesn't force your application to pause and wait. It also runs directly in web browsers without extra setup. It supports all current OpenAI models, from the latest o-series down to older ones like text-davinci.