Which model is better: GPT-5.6 Luna or GPT-5.6 Terra?

GPT-5.6 Luna is 88.0% cheaper for input tokens ($0.18 vs. $1.50 per 1M tokens) and $0.72 vs. $6.00 for output tokens (8.3x cost difference). In terms of operational performance, GPT-5.6 Luna delivers faster response latency with 90ms TTFT (120ms faster than GPT-5.6 Terra). GPT-5.6 Terra leads coding benchmarks at 65.4% SWE-bench vs. 48.5% for GPT-5.6 Luna.
Verified daily via automated API latency tests and official documentation.

Verified Performance & Unit Economics Delta

Daily synchronized metrics from synthetic latency endpoints and benchmark evaluations.

Metric / Dimension GPT-5.6 Luna GPT-5.6 Terra Net Delta / Advantage
Input Cost / 1M Tokens $0.18 $1.50 GPT-5.6 Luna is 8.3x cheaper
Output Cost / 1M Tokens $0.72 $6.00 GPT-5.6 Luna (88% lower)
Avg TTFT Response Latency 90ms 210ms GPT-5.6 Luna (+120ms faster)
SWE-bench Verified (Coding) 48.5% 65.4% GPT-5.6 Terra (+16.9% lead)
Inference Value Score (IVR) 99.9 / 100 72.5 / 100 GPT-5.6 Luna (+27.4 pts)

Interactive Monthly Token Economics & ROI Forecaster

Model your expected production workload across prompt (input) and completion (output) tokens.

Live Calculation Engine
10.0M Tokens
100K 50M 250M 500M+
2.5M Tokens
100K 10M 50M 100M+

Estimated Monthly Spend

GPT-5.6 Luna $5.45

$0.18/1M in · $0.72/1M out

GPT-5.6 Terra $67.50

$1.5/1M in · $6/1M out

Projected Monthly Cost Reduction
$62.05 / mo
(91.9% lower cost)
A

When to Choose GPT-5.6 Luna

Choose GPT-5.6 Luna when you need Real-time conversational agents, high-volume classification, intent detection, and low-latency interactive apps. and have an infrastructure budget aligned with $0.18/1M tokens.

B

When to Choose GPT-5.6 Terra

Choose GPT-5.6 Terra when you need Mainstream production enterprise workflows, high-throughput developer copilots, and structured data synthesis. and prioritize OpenAI ecosystem integration at $1.50/1M tokens.

Related Questions & Decision Factors

Which is cheaper: GPT-5.6 Luna or GPT-5.6 Terra?

GPT-5.6 Luna is cheaper at $0.18/1M input tokens compared to $1.50/1M for GPT-5.6 Terra.

Which model has lower latency: GPT-5.6 Luna or GPT-5.6 Terra?

GPT-5.6 Luna delivers faster response times with an average TTFT of 90ms vs 210ms for GPT-5.6 Terra.

When should you choose GPT-5.6 Luna?

Choose GPT-5.6 Luna when you need Real-time conversational agents, high-volume classification, intent detection, and low-latency interactive apps. and have an infrastructure budget aligned with $0.18/1M tokens.

When should you choose GPT-5.6 Terra?

Choose GPT-5.6 Terra when you need Mainstream production enterprise workflows, high-throughput developer copilots, and structured data synthesis. and prioritize OpenAI ecosystem integration at $1.50/1M tokens.

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