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GPT 5.6 prices cut 20–80%; intelligence cost drops 13× in 4 months

GPT 5.6 prices cut 20–80%; intelligence cost drops 13× in 4 months

3 Key Points

  1. What happened

    OpenAI cut GPT-5.6 Luna prices by 80% (now $0.20 per million input tokens and $1.20 per million output tokens) and Terra by 20% (to $2/$12), while launching Sol Fast mode at 2.5× speed for 2× the price. The cuts follow systemic efficiency gains: self-optimization reduced serving costs by 20%, speculative decoding improved token efficiency by over 15%, and optimizations to KV caching, context bloat avoidance, and prompt caching lowered infrastructure demands.

  2. Why it matters

    GPT-5.4 full intelligence (scored 51 on Artificial Analysis Cost per Task benchmark) cost $2.50/$15 four months ago; that same intelligence level is now available in Luna at $0.20/$1.20—roughly one-thirteenth the token price. For workflows like auto-review in ChatGPT and Codex CLI moving from GPT-5.4 to Luna, OpenAI projects roughly 10× lower cost. This undercuts open models like DeepSeek and specialized cheap models like Gemini Flash-Lite on cost-per-task.

  3. What to watch

    OpenAI's pricing gains reflect sustained deflationary pressure on commodity AI inference. The body notes an annualized rate of roughly 2000× cost reduction per year (though benchmarks like Artificial Analysis may be partially trained-to), and the article frames this as an acceleration beyond the 1000× drop over 18 months observed a year prior. Sol Fast mode is available in the API; Luna and Terra cuts are effective immediately.

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Context & Analysis

The article traces a striking pattern of sustained cost reduction in AI inference. A year ago, holding model quality constant (measured by LMSys Elo), GPT-4-level intelligence fell 1000× in cost over 18 months; the new data suggest this deflation has not only continued but accelerated. The specific claim—that GPT-5.4 intelligence now costs roughly one-thirteenth what it did four months earlier—translates to an annualized rate the article frames as "roughly 2000× a year," though it hedges this with the caveat that public benchmarks like Artificial Analysis may be partially trained-to, whereas Elos resist direct optimization.

The price cuts are tied directly to systems-level improvements across three layers: the model itself (self-optimization where GPT-5.6 analyzed production traffic and autonomously rewrote serving kernels), the inference stack (speculative decoding and KV caching tuning), and the agentic harness (context bloat avoidance and prompt caching). This multi-layer optimization appears to reflect a shift from low-hanging fruit (moving from completions to reasoning, from dense to mixture-of-experts) to harder architectural and infrastructure wins. The practical impact is immediate: teams using Codex and ChatGPT are moving auto-review from GPT-5.4 to Luna with an expected 10× cost reduction.

The article also notes that on cost-per-task benchmarks, OpenAI has "beat even open models like DeepSeek, GLM, and MiniMax, and dedicated cheap-but-good models like Gemini Flash-Lite," positioning proprietary inference as the cheapest option for non-finetuned intelligence—a reversal from prior periods when open models offered better unit economics.

FAQ
Which GPT-5.6 models got price cuts and by how much?
GPT-5.6 Luna was cut 80% to $0.20 per million input tokens and $1.20 per million output tokens; GPT-5.6 Terra dropped 20% to $2/$12. GPT-5.6 Sol also got a new Fast mode offering up to 2.5× speed for 2× the standard price with no change in intelligence.
How much cheaper is GPT-5.4 intelligence now compared to four months ago?
GPT-5.4 full at high quality scored 51, the same benchmark level Luna now reaches. GPT-5.4 cost $2.50/$15; Luna now costs $0.20/$1.20—roughly one-thirteenth the token price.
What technical changes enabled the price cuts?
OpenAI cited self-optimization (reducing serving costs by 20%), speculative decoding (improving token-generation efficiency by over 15%), optimized KV caching and batching, avoiding context bloat through deferred tool discovery and 10,000-token output caps, and prompt caching to reuse previously computed data.

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