The Big Three in 2025
Three labs dominate the frontier model space: OpenAI with GPT-4o, Anthropic with Claude 3.5 Sonnet, and Google with Gemini 1.5 Pro. Each has distinct strengths, pricing, and best-fit use cases. Here is a structured comparison.
Reasoning and Instruction Following
Claude 3.5 Sonnet leads on complex instruction following, multi-step reasoning, and avoiding spurious refusals. Its constitutional training makes it the most reliable for nuanced tasks where the model must balance competing constraints.
GPT-4o is the most versatile — strong across all categories with the broadest ecosystem (plugins, assistants, fine-tuning APIs).
Gemini 1.5 Pro leads on document understanding and analysis tasks, particularly when combining text and images from the same source.
Coding
- GPT-4o: Best at generating syntactically correct code across many languages.
- Claude 3.5 Sonnet: Best at understanding existing codebases and making precise edits without breaking surrounding code.
- Gemini 1.5 Pro: Strong at code + data tasks — writing code that analyzes data, generating SQL.
Context Window
| Model | Context Window | Effective Accuracy |
|---|---|---|
| GPT-4o | 128K tokens | Degrades after ~32K |
| Claude 3.5 Sonnet | 200K tokens | Strong to ~100K |
| Gemini 1.5 Pro | 1M tokens | Reasonable to 500K |
Cost Per Million Tokens (Output)
| Model | Input | Output |
|---|---|---|
| GPT-4o | $5 | $15 |
| Claude 3.5 Sonnet | $3 | $15 |
| Gemini 1.5 Pro | $3.50 | $10.50 |
| GPT-4o-mini | $0.15 | $0.60 |
Our recommendation: Use Claude 3.5 Sonnet for complex tasks, GPT-4o-mini for high-volume simple tasks, and Gemini 1.5 Pro when you need very long context or multimodal document analysis.
