GPT-5.5 vs Claude Sonnet 5
How GPT-5.5 (OpenAI) and Claude Sonnet 5 (Anthropic) compare on price, context window and best-fit use case.
In short: GPT-5.5 is best for Highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost, while Claude Sonnet 5 suits Running AI agents affordably, multi-step automation, coding assistants and high-scale chat where you want near-flagship quality at lower cost. On price it's $5.00 vs $2.00 per 1M input tokens; on context, ~1.05M tokens (128K max output) vs 1M tokens (verify — not yet published for Sonnet 5).
| Spec | GPT-5.5 | Claude Sonnet 5 |
|---|---|---|
| Developer | OpenAI | Anthropic |
| Context window | ~1.05M tokens (128K max output) | 1M tokens (verify — not yet published for Sonnet 5) |
| Input price /1M | $5.00 | $2.00 |
| Output price /1M | $30.00 | $10.00 |
| Modalities | text, image | text, image |
| Best for | Highest-stakes reasoning, complex agents, and frontier coding tasks where capability outweighs cost. | Running AI agents affordably, multi-step automation, coding assistants and high-scale chat where you want near-flagship quality at lower cost. |
GPT-5.5
- State-of-the-art reasoning and agentic workflows
- 1M+ context window
- Strong coding and tool use
- Multimodal (text + image input)
Claude Sonnet 5
- Highly agentic (planning + autonomous tool/browser/terminal use)
- Strong agentic coding
- Near-Opus-4.8 quality at much lower cost
- Great for high-scale agents and chatbots