Compare models
Put up to 4 models beside each other — token prices, context windows, capabilities and provider, from the same catalogue the model pages read.
4 is the maximum. Remove one to add another.
| Attribute | Claude Sonnet 5.5claude-sonnet-5.5 | GPT-6 Astra Progpt-6-astra-pro | S1s1 | GPT-6 Lunagpt-6-luna |
|---|---|---|---|---|
| Pricing | ||||
| Input | $2.00 / 1M | $10.00 / 1M | $0 / 1M | $0.10 / 1M |
| Output | $10.00 / 1M | $50.00 / 1M | $0 / 1M | $0.50 / 1M |
| Cache Write (5m) | $2.50 / 1M | $10.00 / 1M | Not applicable | $0.10 / 1M |
| Cache Write (1h) | $4.00 / 1M | $10.00 / 1M | Not applicable | $0.10 / 1M |
| Cache Read | $0.20 / 1M | $10.00 / 1M | Not applicable | $0.10 / 1M |
| Web Search | $0 / 1M | $0 / 1M | $0 / 1M | $0 / 1M |
| Context | ||||
| Max context | 1M | 1M | N/A | 1.1M |
| Max output | N/A | N/A | N/A | N/A |
| Capabilities | ||||
| Vision | Yes | Yes | No | Yes |
| Function Calling | Yes | Yes | No | Yes |
| JSON Mode | Yes | Yes | No | Yes |
| Streaming | Yes | Yes | No | Yes |
| Catalogue | ||||
| Provider | Anthropic | OpenAI | Fish Audio | OpenAI |
| Category | chat | chat | voice | chat |
| Charge type | Pay As You Go | Pay As You Go | Pay As You Go | Pay As You Go |
| Released | — | — | 2026-07-29 | — |
| Description | ||||
| Summary | Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, serving as a direct upgrade to Sonnet 5. It excels at feature development, bug fixing, and creating polished documents, presentations, and spreadsheets, while offering clearer writing and communication than its predecessor. | GPT-6 Astra Pro uses the same underlying model as GPT-6 Astra, but runs with reasoning.mode set to pro for higher-quality responses on complex tasks. Optimized for deeper reasoning, greater accuracy, and more reliable multi-step execution, it is well suited for demanding coding, analysis, and agentic workflows where solution quality takes priority over speed and cost. | Fish Audio S1 text-to-speech. Billed per UTF-8 byte of input text. | GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, optimized for high-volume and latency-sensitive workloads such as chat, classification, and lightweight agentic tasks. It combines low-cost, responsive inference with the GPT-6 family’s improvements in factual reliability and clear, concise communication. At higher reasoning effort, GPT-6 Luna can also handle complex software engineering and computer-use workflows that previously required a Sol-tier model, making it a versatile choice for scalable production applications that need to balance speed, cost, and capability. |