Fundamentals

Temperature, Top-p, and You: Tuning Model Creativity

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Two knobs quietly shape almost every answer a model gives you: temperature and top-p. Most people never touch them, which is fine for chat — but if you're generating at scale or wiring prompts into a product, understanding them is the difference between output that's reliably on-target and output that surprises you at the worst moment.

What they actually do

At each step, the model has a ranked list of possible next words with probabilities. These two settings decide how adventurously it picks from that list.

  • Temperature flattens or sharpens the probabilities. Low temperature makes the model favor the most likely word (focused, repeatable). High temperature spreads the odds (varied, surprising, sometimes off).
  • Top-p (nucleus sampling) caps which words are even eligible — it keeps only the smallest set of top words whose probabilities add up to p. Low top-p means "only consider the safe, obvious options."

They overlap, so you usually tune one and leave the other near default rather than cranking both.

Sane defaults by task

TaskTemperatureWhy
Factual answers, extraction0.0 – 0.3You want the same right answer every time
Coding0.0 – 0.2Determinism and correctness over flair
Summaries, rewrites0.3 – 0.5Faithful but readable
Marketing copy, brainstorming0.7 – 1.0Variety is the point

If output feels robotic, nudge temperature up. If it drifts, rambles, or invents things, bring it down. Change one setting at a time, or you won't know which knob did what.

The catch most people miss

Higher creativity settings raise the odds of confident nonsense. For anything where accuracy matters — numbers, code, citations — lower is safer, and you make up for the "boring" by writing a richer prompt rather than a hotter setting. A specific, well-structured prompt at temperature 0.2 beats a vague one at 0.9 almost every time.

That's the real lever: the prompt does more for quality than the sampling settings do. If you want to see it, take a flat result, run it through the AI Prompt Refiner to add role, format, and constraints, and compare — usually you'll get the "creativity" you wanted without touching a single knob. And when you're choosing which model to run at all, our guide to picking a model by task pairs naturally with getting these settings right.

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