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Anthropic: Claude Sonnet 5 vs OpenAI: GPT-5.6 Luna

anthropic logoAnthropic: Claude Sonnet 5anthropic/claude-sonnet-5VSopenai logoOpenAI: GPT-5.6 Lunaopenai/gpt-5.6-luna

Anthropic: Claude Sonnet 5 and OpenAI: GPT-5.6 Luna are evenly matched; the right pick depends on your priorities.

MetricAnthropic: Claude Sonnet 5OpenAI: GPT-5.6 Luna
Intelligence Index53.4✓51.2
Coding Index71.5✓71.4
GPQA Diamond91%91%
Design Arena Elo1322✓—
Speed (tokens/sec)61✓60
Latency2.0s1.7s✓
Input price /M$2.00$1.00✓
Output price /M$10.00$6.00✓
Context window1M1.1M✓
CapabilitiesReasoningToolsJSONVisionReasoningToolsJSONVision
Anthropic: Claude Sonnet 5 details →OpenAI: GPT-5.6 Luna details →