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.
| Attribute | Universal-3.5 Prouniversal-3-5-pro | GPT-6 Lunagpt-6-luna | GPT-6.1 Solgpt-6.1-sol |
|---|---|---|---|
| Pricing | |||
| Input | $0 / 1M | $0.10 / 1M | $2.00 / 1M |
| Output | $0 / 1M | $0.50 / 1M | $10.00 / 1M |
| Cache Write (5m) | Not applicable | $0.10 / 1M | $2.00 / 1M |
| Cache Write (1h) | Not applicable | $0.10 / 1M | $2.00 / 1M |
| Cache Read | Not applicable | $0.10 / 1M | $2.00 / 1M |
| Web Search | $0 / 1M | $0 / 1M | $0 / 1M |
| Context | |||
| Max context | N/A | 1.1M | 1M |
| Max output | N/A | N/A | N/A |
| Capabilities | |||
| Vision | No | Yes | Yes |
| Function Calling | No | Yes | Yes |
| JSON Mode | No | Yes | Yes |
| Streaming | No | Yes | Yes |
| Catalogue | |||
| Provider | AssemblyAI | OpenAI | OpenAI |
| Category | voice | chat | chat |
| Charge type | Pay As You Go | Pay As You Go | Pay As You Go |
| Released | 2026-09-22 | — | — |
| Description | |||
| Summary | AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio. | 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. | GPT-6.1 Sol is an upgraded high-end model in OpenAI's GPT-6 series, positioned below the flagship GPT-6 Astra. It is optimized for agentic coding, computer use, document-heavy professional work, and multi-step business automation, delivering near-Astra-level capability at significantly lower cost. Compared with GPT-6 Sol, it offers improved factual reliability and stronger adherence to explicit constraints and user intent, making it well suited for complex, long-running agentic workflows where accurate and dependable execution is critical. |