Which model is better: Claude 3.7 Sonnet or GPT-5.6 Luna?

GPT-5.6 Luna is 94.0% cheaper for input tokens ($0.18 vs. $3.00 per 1M tokens) and $0.72 vs. $15.00 for output tokens (16.7x cost difference). In terms of operational performance, GPT-5.6 Luna delivers faster response latency with 90ms TTFT (560ms faster than Claude 3.7 Sonnet). Claude 3.7 Sonnet leads coding benchmarks at 70.3% 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 Claude 3.7 Sonnet GPT-5.6 Luna Net Delta / Advantage
Input Cost / 1M Tokens $3.00 $0.18 GPT-5.6 Luna is 16.7x cheaper
Output Cost / 1M Tokens $15.00 $0.72 GPT-5.6 Luna (1983.3% lower)
Avg TTFT Response Latency 650ms 90ms GPT-5.6 Luna (+560ms faster)
SWE-bench Verified (Coding) 70.3% 48.5% Claude 3.7 Sonnet (+21.8% lead)
Inference Value Score (IVR) 49.5 / 100 99.9 / 100 GPT-5.6 Luna (+50.4 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

Claude 3.7 Sonnet $5.45

$3/1M in · $15/1M out

GPT-5.6 Luna $67.50

$0.18/1M in · $0.72/1M out

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

When to Choose Claude 3.7 Sonnet

Choose Claude 3.7 Sonnet when you need Agentic coding, deep hybrid reasoning with controllable thinking budgets, and end-to-end software engineering workflows. and have an infrastructure budget aligned with $3.00/1M tokens.

B

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 prioritize OpenAI ecosystem integration at $0.18/1M tokens.

Related Questions & Decision Factors

Which is cheaper: Claude 3.7 Sonnet or GPT-5.6 Luna?

GPT-5.6 Luna is cheaper at $0.18/1M input tokens compared to $3.00/1M for Claude 3.7 Sonnet.

Which model has lower latency: Claude 3.7 Sonnet or GPT-5.6 Luna?

GPT-5.6 Luna delivers faster response times with an average TTFT of 90ms vs 650ms for Claude 3.7 Sonnet.

When should you choose Claude 3.7 Sonnet?

Choose Claude 3.7 Sonnet when you need Agentic coding, deep hybrid reasoning with controllable thinking budgets, and end-to-end software engineering workflows. and have an infrastructure budget aligned with $3.00/1M tokens.

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 prioritize OpenAI ecosystem integration at $0.18/1M tokens.

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