Claude Fable 5 vs Gemini 3.5 Pro: Long Context Reasoning on 1M Tokens Tested (2026)
Claude Fable 5 launched on June 9, 2026, with a 1 million token context window matching what Gemini 3.5 Pro shipped at its February release. For engineering teams building document Q&A, codebase analysis, or multi document reasoning pipelines, the headline context window is the easy comparison. What actually matters is whether the model can reason across that context, not just retrieve from it.