GPT-5.6 Luna
by OpenAI
Today's price · per 1M tokens
Input
$0.200
per 1M tokens
Output
$1.20
per 1M tokens
Blended
$0.700
avg of input & output $/1M
Cached input
$0.020
10% of input — prompt caching
Source: official OpenAI pricing · read Aug 1, 2026
MODELPRICEWATCH.COM · 2026-08-01
Overview
Low-cost, high-volume GPT-5.6 tier — the efficient option in the Sol/Terra/Luna scheme, for cost-sensitive workloads. 1.05M context, 128K max output, text + image input. $0.20/$1.20 per 1M tokens (cached input $0.02).
Capabilities
struck through = not supportedInput 2/5
Text ✓
Image ✓
Audio
Video
PDF
Output 1/5
Text ✓
Image
Audio
Video
Embedding
Features 4/9
Prompt caching ✓
Reasoning ✓
Coding
Fast inference
Long context ✓
Open weights
Multimodal ✓
Web search
Realtime
Benchmark performance
accuracy % · higher is betterAvg benchmark score90.7%
Perf per $/Mtok25.9
GPQA Diamond
92.3%
SWE-Bench Verified
93%
Terminal-Bench 2.1
84.3%
HumanEval
93%
Independent composite scores
- AA Intelligence Index: 51.2 (Artificial Analysis composite across reasoning, knowledge and coding evals)
- AA Agentic Index: 45.6 (Tool use, planning, autonomy)
- AA-Omniscience Index: -11.2 (−100–100)
- GDPval-AA v2: 1581.9 ELO (Real-world work tasks, human baseline = 1000)
How it stacks up
- Ranks #2 of 68 benchmarked models by average score
- Ranks #16 of 133 comparably-measured models by percentile score, across 8 independent measurements
- Ranks #11 of 133 comparably-tested models by normalized performance per dollar
- Strongest at HumanEval — 93%, #5 of 45
184.6 tokens/sec output
Source: Vellum LLM Leaderboard · updated Aug 1, 2026 · See full rankings →
Specifications
- Provider
- OpenAI
- Context window
- 1M tokens
- Modality
- text, image
- Parameters
- Proprietary
- Open source
- No — proprietary
- Released
- Jul 9, 2026
- Status
- Current
- Last updated
- Aug 1, 2026
- Tags
Availability verified: Aug 1, 2026 — listed on OpenAI's own page