GPT-6 Astra (thinking) vs Claude Fable 5

Detailed comparison of capabilities, features, and performance.

GPT-6 Astra (thinking)

GPT-6 Astra (thinking)

OpenAI
VS
Claude Fable 5

Claude Fable 5

Anthropic
Feature GPT-6 Astra (thinking) Claude Fable 5
AI Lab OpenAI Anthropic
Context Size 1,050,000 tokens 1,000,000 tokens
Max Output Size 128,000 tokens 128,000 tokens
Frontier Model Yes Yes
Vision Support Yes Yes
Description GPT-6 Astra configured with high reasoning effort for the hardest end-to-end professional work. Anthropic's most capable widely released model, with a 1M token context window, 128k max output, and always-on adaptive thinking.

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