Claude 3.5 Sonnet vs GPT-4o vs Gemini 1.5 Pro for reasoning

Summary from production A/Bs: - Claude 3.5 Sonnet: Strong at tool use and long-context summarization; polite and safe defaults. Occasionally verbose. - GPT-4o: Excellent coding and math, robust function calling, fast realtime options. Can be costlier depending on context. - Gemini 1.5 Pro: Very long context and good grounding with citations; responses can vary by prompt framing. Use-cases: - Code review and generation: GPT-4o wins slightly. - Policy summarization and analysis: Claude often preferred by SMEs. - Ingesting huge docs and multi-file tasks: Gemini shines with context. Tip: Router based on task and budget; keep a fallback and cache. Always add a reranker for RAG to reduce model variance.