Moderate Tokens Question 73 of 223

How do you count tokens before calling an API?

GenAI / LLM · Speak this in 60–90 seconds · Faridabad & Delhi NCR

PICTURE THIS: A SENTENCE BECOMES TOKENS

The model does not read letters like humans. It reads these pieces, then predicts the next one.

Simple meaning

Use the same tokenizer the model uses, such as tiktoken for many OpenAI models.

1

WHY — Tokens instead of words?

LLMs use tokens (not full words) because it helps them:

This is a process

question about Tokens.

Panels listen for order,

trade-offs, and what you would actually do on a GenAI / LLM project - not buzzwords.

Stable token IDs

Each piece maps to a number the network can learn.

Fits the model

Fixed pieces are what transformers expect as input.

2

STEPS — What happens with tokens?

Before the model can read a sentence, it goes through these steps:

  1. 1
    Use the same tokenizer

    the model uses, such as tiktoken for many OpenAI models.

  2. 2
    Character heuristics like four

    characters per token are only rough.

  3. 3
    Count messages after chat-template

    formatting, including tools and retrieved context.

  4. 4
    Context mix

    Attention looks at nearby tokens together.

  5. 5
    Next token

    The model scores what should come next.

  6. 6
    Decode

    IDs turn back into readable text.

3

EXAMPLE — See it in action

Let's see how a real sentence is tokenized (tokens may vary by model):

Input text
“Character heuristics like four characters per token are only rough.”
Tokenized output
Characterheuristicslikefourcharactersper
Token IDs (example)
2987408337471632900

Note: Actual tokens and IDs depend on the tokenizer (e.g., GPT, Llama, etc.).

Key takeaway

Use the same tokenizer the model uses, such as tiktoken for many OpenAI models. Character heuristics like four characters per token are only rough.

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