Do you know how ChatGPT tokens work?

Last updated by Jack Pettit [SSW] 5 months ago.See history

GPT models utilize "tokens" as their smallest units of text. These tokens can be as small as a single character, like "a," or as large as a word, such as "apple." Interestingly, tokens can also represent parts of a word.

For instance, in GPT's perspective, the word "unhappiness" could be tokenized into three parts: "un," "happi," and "ness." Each of these parts is considered a separate token. This flexible understanding of tokens is what allows GPT models to efficiently break down text data for analysis.

How GPT Models Utilize Tokens

These models are trained on vast amounts of text data, wherein the data is divided into tokens. Through this process, the model comprehends the statistical relationships between tokens, enabling it to generate new text that mirrors the style and content it was trained on.

The Influence of Tokens on ChatGPT's Performance

ChatGPT breaks down an input message into tokens and uses these to generate a sequence of output tokens. This reflects what it has learned during training. The model can process only a specific number of tokens in a single instance, counted as the token limit. This limit is around 4000 for GPT-3.5 and about 8000 for GPT-4.

For example, if you send a message of 10 tokens to ChatGPT and it responds with a message of 20 tokens, that would count as 30 tokens used. The count includes both input and output tokens.

How Token Allocation Impacts Response Quality

ChatGPT “remembers” elements of a conversation until it reaches its token limit. Having longer conversations helps it to retain context as you refine the responses, which can be useful (See rule on using chained prompting). However, it is important to be mindful that although longer conversations give more context, at a certain point (its token limit), ChatGPT will start to “forget” earlier parts of a conversation. This results in truncated responses or loss of context.

Tips for Managing Tokens

1. Limit prompt length: Since the number of input tokens affects the total token count, keep your prompts concise, especially if you expect a long answer. This leaves more room for ChatGPT's responses.

Tip: You can use the ChatGPT Tokenizer to see how many tokens a piece of text uses.

2. Control the length of responses: If you are planning on having a longer conversation with ChatGPT, you can specify a length limit. This prevents it from generating overly long responses that consume too many tokens.


  • "List the most important differences between Python and Java. Be concise."
  • "Explain the principles of RESTful API design. Give only 4 bullet points."

3. Use clear prompting: Direct prompts can lead to more efficient token usage. Try to be specific and clear in your prompts to get a better response that uses fewer tokens and doesn’t give you background info you’re not interested in.

Tip: Refining prompts can improve your ChatGPT efficiency. See the rule on creating ChatGPT prompt templates for repeatable tasks.

4. Balance complex queries: There are scenarios where complex queries or long explanations may require a large number of tokens (e.g. you are inputing a multi-page document for ChatGPT to summarize). In such cases, it's essential to be mindful of the token count. You can use techniques like summarization or abstraction to reduce the token count while keeping the important information. See rule Do you summarize long conversations for better context retention?


  • Summarize your last reply while keeping all the important points”
  • Abstract the main arguments in your last response”
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