README

PHP port for openai/tiktoken (most)

Supported encodings

• gpt-3.5-turbo
• gpt-4
• gpt-4o
• gpt-oss
• gpt-5
• more ...

For available encodings, see src/EncodingFactory.php

Installation

composer require danny50610/bpe-tokeniser

Example

GPT-5 (o200k_base)

use Danny50610\BpeTokeniser\EncodingFactory;

$enc = EncodingFactory::createByModelName('gpt-5-2025-08-07');

var_dump($enc->encode("hello world"));
/**
 * output: 
 * array(2) {
 *  [0]=>
 *  int(24912)
 *  [1]=>
 *  int(2375)
 * }
 */

var_dump($enc->decode($enc->encode("hello world")));
// output: string(11) "hello world"

GPT-4 / GPT-3.5-Turbo (cl100k_base)

use Danny50610\BpeTokeniser\EncodingFactory;

$enc = EncodingFactory::createByEncodingName('cl100k_base');

var_dump($enc->encode("hello world"));
/**
 * output: 
 * array(2) {
 *  [0]=>
 *  int(15339)
 *  [1]=>
 *  int(1917)
 * }
 */

var_dump($enc->decode($enc->encode("hello world")));
// output: string(11) "hello world"

use Danny50610\BpeTokeniser\EncodingFactory;

$enc = EncodingFactory::createByModelName('gpt-3.5-turbo');

var_dump($enc->decode($enc->encode("hello world")));
// output: string(11) "hello world"