Claude Sonnet 4 vs GPT-5.6 Luna

Price, context window & benchmark comparison

Anthropic

Claude Sonnet 4

Anthropic
$3.00 / $15.00
Input / Output · per 1M tokens
VS
OpenAI

GPT-5.6 Luna

OpenAI
$0.20 / $1.20
Input / Output · per 1M tokens
Compare different models
Anthropic
OpenAI
Verdict: GPT-5.6 Luna is 13.3× cheaper than Claude Sonnet 4 on a typical 3:1 input/output mix. GPT-5.6 Luna scores higher on the Artificial Analysis Intelligence Index (23.8 vs 18.9). GPT-5.6 Luna has the larger context window (1.1M vs 200K).
Claude Sonnet 4GPT-5.6 Luna
Input price / 1M$3.00$0.20
Output price / 1M$15.00$1.20
Blended price (3:1)$6.00$0.45
Cached input / 1M$0.30$0.02
Context window200K1.1M
Max output64K128K
Intelligence index18.923.8
Coding index37.671.4
Providers—7
Best provider uptime (30m)—100.0%
Vision inputYesYes
ReasoningYesYes
Tool callingYesYes
Released2025-05-222026-07-09
Retirement2026-10-15—

Cost calculator

FAQ

Which is cheaper, Claude Sonnet 4 or GPT-5.6 Luna?

GPT-5.6 Luna is 13.3× cheaper than Claude Sonnet 4 on a typical 3:1 input/output mix.

Claude Sonnet 4 vs GPT-5.6 Luna: which has a bigger context window?

Claude Sonnet 4: 200,000 tokens. GPT-5.6 Luna: 1,050,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: Claude Sonnet 4 ≈ $13,500, GPT-5.6 Luna ≈ $1,000.

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