OpenAI Tokenizer
Official tokenizer for GPT-4, GPT-4o, ChatGPT, and all OpenAI models
Free online tool using OpenAI's tiktoken library
OpenAI Token Pricing (2025)
GPT-4o
GPT-4o mini
GPT-4 Turbo
GPT-3.5 Turbo
💡 Pro tip: Use our tokenizer to calculate exact costs before API calls
Accurate Token Counts
Uses OpenAI's official tiktoken library for 100% accurate token counting across all GPT models.
Cost Calculator
Calculate exact API costs for GPT-4, GPT-3.5, and other OpenAI models before making requests.
Token Visualization
See how OpenAI models break down your text into individual tokens with color-coded display.
How OpenAI Tokenization Works
OpenAI models like GPT-4 and ChatGPT use Byte Pair Encoding (BPE) tokenization. This means text is broken into subword units (tokens) rather than individual characters or whole words.
Example Tokenization:
Key facts about OpenAI tokens:
- 1 token ≈ 4 characters in English
- 1 token ≈ ¾ of a word on average
- 100 tokens ≈ 75 words
- Context limits: GPT-4 (8K-128K), GPT-3.5 (4K-16K)
Start Using the OpenAI Tokenizer
Instantly count tokens, visualize tokenization, and optimize your prompts for all OpenAI models including GPT-4, ChatGPT, and GPT-3.5.
Open Tokenizer Tool →Supported OpenAI Models
GPT-4 Family:
- • GPT-4o (latest)
- • GPT-4o mini
- • GPT-4 Turbo
- • GPT-4-32k
- • GPT-4 (8K context)
GPT-3.5 Family:
- • GPT-3.5-turbo
- • GPT-3.5-turbo-16k
- • text-davinci-003
- • text-davinci-002
Start tokenizing with OpenAI models: