# Extended Thinking

> Extended thinking is a model mode in which the model generates a separate block of reasoning before its final response, with a developer-controlled setting that trades latency and cost for answer quality.

- Identifier: PTL-0085
- Category: Reasoning Models & Test-Time Compute
- Canonical URL: https://protologue.com/t/extended-thinking/
- Also known as: thinking mode, thinking budget, reasoning effort

## Description

Early implementations exposed a fixed thinking token budget; newer Claude models replace it with adaptive thinking, where the model decides how much to reason under a chosen effort level. Vendor guidance for these modes favors high-level instructions about how to think over prescriptive step-by-step scripts.

## Broader terms

- [Reasoning Model](https://protologue.com/t/reasoning-model/)

## Related terms

- [Scratchpad](https://protologue.com/t/scratchpad/)
- [Chain-of-Thought Prompting](https://protologue.com/t/chain-of-thought/)

## Sources

- Anthropic (2025). Building with extended thinking. https://platform.claude.com/docs/en/build-with-claude/extended-thinking

## Cite this entry

Protologue. (2026). Extended Thinking. In Protologue: A Taxonomy of Prompting and LLM Techniques (v1.0.0, PTL-0085). https://protologue.com/t/extended-thinking/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)