What are reasoning tokens in LLMs?

Internal thinking steps models like o1 generate before answering—billed like output, but hidden.

How much more do output tokens cost vs input?

Typically 3-4x across OpenAI, Anthropic, Google—due to sequential generation.

Use non-reasoning models for simple tasks; optimize prompts to minimize internal steps.

Ever stared at your LLM bill and wondered why it's exploding? Blame reasoning tokens—the hidden thinking phase that's pricier than you think.

DevTools Feed Apr 11, 2026 3 min read

Input tokens are cheapest due to parallel processing; outputs and reasoning cost 3-4x more from sequential generation. 𝕏
Reasoning tokens are invisible but billed high—key for o1, Claude thinking modes. 𝕏
Optimize by lean prompts, caching, model choice; future hardware symmetrizes costs. 𝕏

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#LLM pricing #OpenAI costs #reasoning tokens #token optimization

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Originally reported by dev.to