| # ⏳ js-tiktoken |
|
|
| tiktoken is a [BPE](https://en.wikipedia.org/wiki/Byte_pair_encoding) tokeniser for use with |
| OpenAI's models. This is a pure JS port of the original tiktoken library. |
|
|
| Install the library from NPM: |
|
|
| ``` |
| npm install js-tiktoken |
| ``` |
|
|
| ## Lite |
|
|
| You can only load the ranks you need, which will significantly reduce the bundle size: |
|
|
| ```typescript |
| import { Tiktoken } from "js-tiktoken/lite"; |
| import o200k_base from "js-tiktoken/ranks/o200k_base"; |
| |
| const enc = new Tiktoken(o200k_base); |
| assert(enc.decode(enc.encode("hello world")) === "hello world"); |
| ``` |
|
|
| Alternatively, encodings can be loaded dynamically from our CDN hosted on Cloudflare Pages. |
|
|
| ```typescript |
| import { Tiktoken } from "js-tiktoken/lite"; |
| |
| const res = await fetch(`https://tiktoken.pages.dev/js/o200k_base.json`); |
| const o200k_base = await res.json(); |
| |
| const enc = new Tiktoken(o200k_base); |
| assert(enc.decode(enc.encode("hello world")) === "hello world"); |
| ``` |
|
|
| ## Full usage |
|
|
| If you need all the OpenAI tokenizers, you can import the entire library: |
|
|
| > [!CAUTION] |
| > This will include all the OpenAI tokenizers, which may significantly increase the bundle size. See |
|
|
| ```typescript |
| import assert from "node:assert"; |
| import { getEncoding, encodingForModel } from "js-tiktoken"; |
| |
| const enc = getEncoding("gpt2"); |
| assert(enc.decode(enc.encode("hello world")) === "hello world"); |
| ``` |
|
|