Overview
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...
Sakana: Fugu Ultra in depth
Sakana: Fugu Ultra, built by Sakana AI, sits in the chatbots & llms space and is a paid tool starting at $5.00/1M tokens. Our editors rate it 9.2 out of 10 based on capability, ecosystem and value. It handles a context window of 1,000,000 tokens.
On the feature side, Sakana: Fugu Ultra brings 1,000,000-token context window, vision (image input), reasoning / chain-of-thought and tool / function calling. These are the capabilities that most shape day-to-day use and separate it from thinner alternatives.
Sakana: Fugu Ultra is most often chosen for research and writing. If that matches your goals, it's a strong candidate to shortlist.
Key features
- ✓1,000,000-token context window
- ✓Vision (image input)
- ✓Reasoning / chain-of-thought
- ✓Tool / function calling
- ✓Structured (JSON) outputs
- ✓Native web search
Pricing
Pros
Cons
Who should use Sakana: Fugu Ultra
- →Anyone looking for a chatbots & llms tool from Sakana AI.
- →Teams and individuals focused on research and writing.
- →Workflows that need a 1,000,000 tokens context window.
Who should look elsewhere
- →Anyone who needs a free tier — this tool is paid only.
Best for
Sakana: Fugu Ultra alternatives
See all alternatives →Claude
Anthropic
Claude is Anthropic's family of AI assistants, known for long-context reasoning, careful writing and strong coding ability. The Opus, Sonnet and Haiku tiers let you trade off intelligence, speed and cost. Claude excels at nuanced analysis, document understanding and agentic coding workflows, and is a favourite among developers and writers who value clarity.
ChatGPT
OpenAI
ChatGPT is OpenAI's flagship conversational AI, powering hundreds of millions of weekly users across web, mobile and API. Built on the GPT-4o and GPT-5 family of models, it handles text, images, voice and code in a single interface. With browsing, data analysis, custom GPTs and a vast plugin ecosystem, it remains the default assistant for most knowledge workers.
Gemini
Google DeepMind
Gemini is Google's natively multimodal model family, deeply integrated across Search, Workspace, Android and the Pixel line. Its standout feature is an enormous context window of up to one to two million tokens, ideal for analysing long videos, codebases and document sets. Gemini blends Google's real-time knowledge with strong reasoning and is available free in many products.
Anthropic: Claude Sonnet 5
Anthropic
Sonnet 5 is Anthropic's most capable Sonnet-class model, with frontier performance across coding, agents, and professional work. It supports adaptive thinking with selectable reasoning effort levels (low, medium, high, max,...
Anthropic: Claude Fable Latest
~anthropic
This model always redirects to the latest model in the Claude Fable family.
Frequently asked questions
Q. Is Sakana: Fugu Ultra free?
No — Sakana: Fugu Ultra is a paid tool, starting at $5.00/1M tokens.
Q. How much does Sakana: Fugu Ultra cost?
Sakana: Fugu Ultra starts at $5.00/1M tokens. API usage is around $5 per 1M input tokens and $30 per 1M output tokens.
Q. What is Sakana: Fugu Ultra best for?
Sakana: Fugu Ultra is best suited to research and writing, within the chatbots & llms category.
Q. What are the best Sakana: Fugu Ultra alternatives?
Popular alternatives to Sakana: Fugu Ultra include Claude, ChatGPT, Gemini and Anthropic: Claude Sonnet 5. Each trades off price, quality and ecosystem differently.
How we rate AI tools
Our quality score weighs capability on real tasks, breadth of features and integrations, pricing and value, and how actively the tool is maintained. Scores are editorial guidance, not benchmarks — always trial a tool on your own workflow before committing. Pricing and features change frequently, so verify current details on the official site.
Ready to try Sakana: Fugu Ultra?
Start with the official plans and upgrade as you grow.
Visit Sakana: Fugu Ultra →