Understanding Temperature and Top-P in LLM Sampling

  • author: "Vikas Dhyani"
  • date: "2026-03-09"
  • read_time: "~1 min"

Tuning Large Language Models for specific software tasks goes beyond writing instructions. Developers must configure the model's sampling parameters to control creativity, randomness, and determinism. The two main parameters are Temperature and Top-P (Nucleus Sampling).

Tuning Parameters

  • Temperature: Controls the scaling of token probability distributions.
    • Low Temp (0.0 - 0.2): Highly deterministic, repetitive, factual. Essential for code generation and JSON schemas.
    • High Temp (0.7 - 1.0): Creative, diverse, random. Good for brainstorming, creative copy, or character dialogue.
  • Top-P: Restricts token choices to a cumulative probability percentage. At Top-P=0.9, the model only selects from tokens comprising the top 90% of probability distributions, discarding unlikely words.

// Configure parameters based on task type
const apiConfig = {
    codeGeneration: { temperature: 0.0, topP: 0.1 },
    blogWriting: { temperature: 0.7, topP: 0.9 }
};

Best Practice

Developers should avoid editing both parameters concurrently; tune temperature first to adjust creativity, and use default Top-P, or vice versa.

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