GPT-6 Astra Pro is the same underlying model as [GPT-6 Astra](https://openrouter.ai/openai/gpt-6-astra), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://develope…
Model details →OpenAI: GPT-6 Astra Pro vs Sakana: Fugu Ultra
Sakana: Fugu Ultra wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
Fugu Ultra is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route...
Model details →Side-by-side comparison
| Capability | OpenAI: GPT-6 Astra Pro | Sakana: Fugu Ultra | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1.1M | 1M | 🏆 OpenAI: GPT-6 Astra Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $5.00 | 🏆 Sakana: Fugu Ultra |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $30.00 | 🏆 Sakana: Fugu Ultra |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is OpenAI: GPT-6 Astra Pro better than Sakana: Fugu Ultra?
Sakana: Fugu Ultra wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between OpenAI: GPT-6 Astra Pro and Sakana: Fugu Ultra?
Input: $10.00 vs $5.00 per 1M tokens. Output: $50.00 vs $30.00 per 1M tokens.
What context windows do OpenAI: GPT-6 Astra Pro and Sakana: Fugu Ultra support?
OpenAI: GPT-6 Astra Pro supports up to 1.1M tokens. Sakana: Fugu Ultra supports up to 1M tokens.
Do both OpenAI: GPT-6 Astra Pro and Sakana: Fugu Ultra support tool calling?
OpenAI: GPT-6 Astra Pro: yes. Sakana: Fugu Ultra: yes.