Choose Anthropic: Claude Sonnet 4.5 (batch) if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
Anthropic: Claude Sonnet 4.5 (batch) vs Sakana: Fugu Max
Sakana: Fugu Max comes out ahead on the data we track: 2 advantages and none for Anthropic: Claude Sonnet 4.5 (batch).
Key numbers
| Spec | Anthropic: Claude Sonnet 4.5 (batch) | Sakana: Fugu Max |
|---|---|---|
| Provider | Anthropic | Sakana |
| Input price (per 1M tokens) | $1.50 | $2.00 |
| Output price (per 1M tokens) | $7.50 | $6.00 |
| Blended price (3:1 input/output) | $3.00 | $3.00 |
| Cheaper than … of all models we track | 20% | 20% |
| Context window | 1M tokens (~1,500 pages) | 1M tokens (~1,500 pages) |
| Larger context than … of all models | 68% | 68% |
| Max output per response | 64K tokens (~48,000 words) | 128K tokens (~96,000 words) |
| Input types | text, image, file | text, image, file |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-09-29 | 2026-09-11 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | Anthropic: Claude Sonnet 4.5 (batch) | Sakana: Fugu Max | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $263 | $270 | Anthropic: Claude Sonnet 4.5 (batch) saves $7.50 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $255 | $300 | Anthropic: Claude Sonnet 4.5 (batch) saves $45.00 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $270 | $312 | Anthropic: Claude Sonnet 4.5 (batch) saves $42.00 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $165 | $196 | Anthropic: Claude Sonnet 4.5 (batch) saves $31.00 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $82.50 | $106 | Anthropic: Claude Sonnet 4.5 (batch) saves $23.50 |
Capabilities side by side
| Capability | Anthropic: Claude Sonnet 4.5 (batch) | Sakana: Fugu Max | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | ✓ Yes | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | ✓ Yes | ✓ Yes | answer from live web results |
| Seed (reproducible sampling) | — | — | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- Anthropic: Claude Sonnet 4.5 (batch): price unchanged since we started tracking it on 2026-08-07.
- Sakana: Fugu Max: price unchanged since we started tracking it on 2026-09-12.
Which should you choose?
Choose Sakana: Fugu Max if…
- you generate long outputs in one go — up to 128K tokens (about 96,000 words) per response
- you want the newer model — released 2026-09-11, 12 months after the other
Frequently asked questions
Is Anthropic: Claude Sonnet 4.5 (batch) better than Sakana: Fugu Max?
Sakana: Fugu Max comes out ahead on the data we track: 2 advantages and none for Anthropic: Claude Sonnet 4.5 (batch).
Which is cheaper, Anthropic: Claude Sonnet 4.5 (batch) or Sakana: Fugu Max?
They cost the same: $3.00 per 1M tokens at a 3:1 input/output mix.
How much do Anthropic: Claude Sonnet 4.5 (batch) and Sakana: Fugu Max cost per million tokens?
Anthropic: Claude Sonnet 4.5 (batch) costs $1.50 per 1M input tokens and $7.50 per 1M output tokens; Sakana: Fugu Max costs $2.00 input and $6.00 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Anthropic: Claude Sonnet 4.5 (batch) or Sakana: Fugu Max?
Both take 1M tokens per request — roughly 1,500 pages of text.
Do Anthropic: Claude Sonnet 4.5 (batch) and Sakana: Fugu Max support function calling and JSON output?
Tool calling — Anthropic: Claude Sonnet 4.5 (batch): yes, Sakana: Fugu Max: yes. JSON-schema structured output — Anthropic: Claude Sonnet 4.5 (batch): yes, Sakana: Fugu Max: yes.
Can Anthropic: Claude Sonnet 4.5 (batch) or Sakana: Fugu Max read images?
Yes, both accept image input.
Is Anthropic: Claude Sonnet 4.5 (batch) or Sakana: Fugu Max free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of Anthropic: Claude Sonnet 4.5 (batch) and Sakana: Fugu Max?
Anthropic: Claude Sonnet 4.5 (batch) can write up to 64K tokens (about 48,000 words) per response; Sakana: Fugu Max up to 128K (about 96,000 words).
When were Anthropic: Claude Sonnet 4.5 (batch) and Sakana: Fugu Max released?
Anthropic: Claude Sonnet 4.5 (batch) was listed on 2025-09-29; Sakana: Fugu Max on 2026-09-11.
About the two models
Anthropic: Claude Sonnet 4.5 (batch)
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with...
Full Anthropic: Claude Sonnet 4.5 (batch) specs →Sakana: Fugu Max
Fugu Max is the cost-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...
Full Sakana: Fugu Max specs →