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 | GPT-5.6 Terragpt-5.6-terra | GPT-6 Solgpt-6-sol | Universal-3.5 Prouniversal-3-5-pro |
|---|---|---|---|
| Pricing | |||
| Input | $2.00 / 1M | $2.00 / 1M | — Not priced per input token |
| Output | $12.00 / 1M | $10.00 / 1M | — Not priced per output token |
| Cache Write (5m) | $2.00 / 1M | $2.00 / 1M | Not applicable |
| Cache Write (1h) | $2.00 / 1M | $2.00 / 1M | Not applicable |
| Cache Read | $2.00 / 1M | $2.00 / 1M | Not applicable |
| Web Search | $0 / 1M | $0 / 1M | $0 / 1M |
| Context | |||
| Max context | 1M | 1.1M | N/A |
| Max output | N/A | N/A | N/A |
| Capabilities | |||
| Vision | Yes | Yes | No |
| Function Calling | Yes | Yes | No |
| JSON Mode | Yes | Yes | No |
| Streaming | Yes | Yes | No |
| Catalogue | |||
| Provider | OpenAI | OpenAI | AssemblyAI |
| Category | chat | chat | voice |
| Charge type | Pay As You Go | Pay As You Go | Pay As You Go |
| Released | — | — | 2026-09-22 |
| Description | |||
| Summary | GPT-5.6 Terra is the balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is designed for everyday coding, reasoning, and agentic workflows, delivering strong performance while balancing capability and cost. Offering near-flagship quality at approximately half the cost of Sol, GPT-5.6 Terra is well suited for production applications that require reliable reasoning, software development, and scalable agent execution. | GPT-6 Sol is OpenAI's cost-efficient high-end model in the GPT-6 series, positioned between the flagship GPT-6 Astra and the fast GPT-6 Luna tier. It is designed for professional knowledge work, agentic coding, business workflow automation, and computer-use tasks, with particular strength in long-horizon software engineering across real-world codebases. GPT-6 Sol approaches Astra-level factual reliability at a significantly lower cost, while sharing its clear and concise communication style. This balance of capability, reliability, and efficiency makes it well suited for production agents, complex engineering workflows, and scalable professional applications | AssemblyAI Universal-3.5 Pro speech-to-text. Billed per second of audio. |