Fugu Ultra vs Claude Opus 5.5
Benchmarks, API Token Pricing, Context Window & Speed Comparison
Related topics (4)
Compare Fugu Ultra by Sakana AI against Claude Opus 5.5 by Anthropic across real-world coding, reasoning, token economics, and latency.
Switch & Compare Any Models
Select any AI models from our verified benchmark database to generate live side-by-side matrices.
Live comparison: no in-depth editorial review has been published for this pair yet.
Fugu Ultra
Premium ReasonerSakana AI's Japanese-multilingual frontier reasoning model developed using evolutionary model merging with million-token capacity.
$1.50 / 1M
$6.00 / 1M
1M tokens
N/A
Claude Opus 5.5
Frontier Intelligence TitanAnthropic's most intelligent model for complex reasoning, research, and strategic analysis.
$4.00 / 1M
$20.00 / 1M
1M tokens
84.6%
Key Differences at a Glance
- Fugu Ultra is 3.1x cheaper for API usage (input + output tokens combined).
- Claude Opus 5.5 is faster at 78 tok/s vs 75 tok/s.
| Feature | Fugu Ultra | Claude Opus 5.5 |
|---|---|---|
Intelligence Index Composite reasoning & knowledge score (0-100) | 86 | 94 |
Provider | Sakana AI | Anthropic |
Input Price Cost per million input tokens | $1.50 / 1M | $4.00 / 1M |
Output Price Cost per million output tokens | $6.00 / 1M | $20.00 / 1M |
Blended Price Weighted 7:2:1 cache:input:output per 1M | $1.01 / 1M | $3.08 / 1M |
Context Window Maximum input + output tokens | 1M tokens~1,500 A4 pages of text | 1M tokens~1,500 A4 pages of text |
Max Output Tokens Per single request | 16K | 128K |
Throughput Speed Tokens generated per second | 75 tok/s | 78 tok/s |
SWE-bench Verified Real-world software engineering | N/A | 84.6% |
GPQA Diamond Graduate-level reasoning | 67% | 82.3% |
Cached Input Price Prompt caching discount per 1M tokens | $0.15 / 1M | $0.40 / 1M |
Who Wins Where?
At-a-glance decision frameworkEvaluations ongoing
Empirical Head-to-Head Benchmark Scores
Official evaluation metrics verified by independent third-party research labs.
Industry benchmark evaluating real-world GitHub issue resolution and multi-file debugging.
Challenging questions created by domain experts to test complex PhD-level reasoning.
Hardened reasoning and academic knowledge benchmark with reduced lucky-guess probability.
Crowdsourced human preference evaluation based on blind, head-to-head model battles.
Extremely difficult, closed-ended questions spanning the frontier of human expert knowledge.
Autonomous multi-step tasks executed inside a real command-line terminal environment.
Research-grade coding problems drawn from real scientific and numerical workloads.
Contamination-free competitive programming problems collected continuously over time.
American Invitational Mathematics Examination — multi-step Olympiad-level reasoning.
Accuracy when reasoning over very large inputs that fill the model context window.
Tokens emitted per second during active generation streaming.
Latency & Response Time
Time to first token (TTFT) and estimated end-to-end response time for a typical 500-token response.
Real-Time Interactive Token Cost Simulator
Adjust sliders to calculate projected monthly cloud API spending with prompt caching discounts.
Fugu Ultra · Strengths & Key Advantages
- World-class Japanese language comprehension and cultural nuance
- Evolutionary model merging techniques yield creative, non-standard problem-solving paths
- Massive 1M token context window with reliable factual recall
Considerations & Trade-offs
- Higher commercial API pricing reflecting premium research tier
- Niche availability outside the Japanese enterprise market
Claude Opus 5.5 · Strengths & Key Advantages
- Unmatched autonomous multi-step agentic coding and refactoring
- Flawless multi-document reasoning over 1M token context with no long-prompt surcharge
- Highest composite Intelligence Index score measured (94/100), leading SWE-bench Verified at 84.6%
- Precise tool execution with robust error-recovery loops
Considerations & Trade-offs
- Premium output pricing ($20.00/M) plus heavy reasoning-token usage (~68K output tokens per complex task) keeps long agentic runs expensive
- Long thinking times at maximum effort can push a single hard agentic task toward ~$3.85+
Token Use & Task Economics
Estimated cost and token consumption to complete one representative agentic task.
| Metric | Fugu Ultra | Claude Opus 5.5 |
|---|---|---|
Cost per Task Estimated USD to finish one task | $0.28 | $3.85 |
Output Tokens / Task Tokens generated per task | 22K | 68K |
Reasoning Tokens / Task Thinking tokens burned per task | 8K | 42K |
Technical Specifications
Architecture, release timeline, capabilities, and modalities.
| Feature | Fugu Ultra | Claude Opus 5.5 |
|---|---|---|
| Official API Model ID (SDK) | fugu-ultra | claude-opus-5-5-20260901 |
| API Protocol | Sakana AI REST API (OpenAI-Compatible) | Anthropic Messages API + AWS Bedrock + Vertex AI |
| Release Date | 2026-06 | 2026-09 |
| Knowledge Cutoff | March 2026 | June 2026 |
| Architecture | Evolutionary Multi-Model Merged Transformer | Extended Autonomous Hybrid Reasoning Transformer |
| Parameters | Confidential / Frontier Merged | Confidential |
| Enterprise Rate Limits (RPM / TPM) | 5,000 – 15,000 RPM (Production Tier) · 4,000,000 – 10,000,000 TPM | 4,000 – 10,000 RPM (Tier 4 + Priority Tier) · 4,000,000 – 10,000,000 TPM |
| Long-Context Tier (>128K/200K) | Flat rate ($1.5/1M in) across full 1000K window | Standard rate up to 200K tokens; 2x input/output tier above 200K tokens |
| Prompt Cache Policy & TTL | Cached input at $0.15/1M tokens | $0.4/1M cached read (90% off); 5-min default & 1-hour extended TTL |
| Computer Use / GUI Agent | API / CLI Tool-Use & DOM Agent ready (no raw pixel desktop click loop) | Supported (Screen coordinate grounding, browser & desktop GUI action loops) |
| MCP & Parallel Tool Calling | Native MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema | Native MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema |
| Web Search Grounding & Sandbox | Supported via external Tavily/Exa Search & E2B/Docker Sandbox tools | Native Web Search Citations + Code Execution Tool + MCP Connectors |
| Official Fine-Tuning Support | API Prompt Engineering & RAG Distillation | Custom Model Tuning via Amazon Bedrock & Prompt Distillation |
| Multimodal Token Billing | Text BPE (~4 chars/token) | Text BPE (~4 chars/token) · Vision (~258–765 tokens per image tile) |
| Quantization & Min GPU VRAM | Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster) · Zero Local VRAM Required (100% Serverless Cloud API) | Cloud-Hosted Proprietary (FP8 / BF16 Tensor Core Cluster) · Zero Local VRAM Required (100% Serverless Cloud API) |
| Safety & Frontier Classification | Sakana AI Production Safety & Alignment Verified | Anthropic RSP ASL-2 / ASL-3 Constitutional Safety Evaluated |
| Enterprise Compliance (ZDR/HIPAA/SOC2) | SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier | SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier |
| Input Modalities | text | text, vision |
| Output Modalities | text | text |
Fugu Ultra vs Claude Opus 5.5: Quick Answers
Which is more intelligent, Fugu Ultra or Claude Opus 5.5?
Claude Opus 5.5 is more intelligent. It scores 94 compared with 86 on the composite Intelligence Index.
Which model is faster?
Claude Opus 5.5 is faster, generating 78 tokens per second compared with 75 tokens per second.
Which model is cheaper to run?
Fugu Ultra is cheaper at $1.01 per 1M tokens blended, compared with $3.08 (7:2:1 cache:input:output ratio).
Which model has lower latency?
Fugu Ultra has lower latency, with a time to first token of 0.54s compared with 1.40s.
Verdict
Choose Fugu Ultra for japanese enterprise intelligence, bilingual translation, and creative scientific exploration, or choose Claude Opus 5.5 for large-scale software development agents, enterprise codebases, and mission-critical scientific synthesis.
Frequently asked questions
Which is cheaper: Fugu Ultra or Claude Opus 5.5?+
Fugu Ultra costs $1.5/1M input and $6/1M output tokens, while Claude Opus 5.5 costs $4/1M input and $20/1M output tokens.
Which model has a larger context window: Fugu Ultra or Claude Opus 5.5?+
Fugu Ultra supports 1M tokens whereas Claude Opus 5.5 supports 1M tokens.
Understand key metrics like context window, token pricing, reasoning mode, and SWE-bench scores in our comprehensive AI glossary.
Related reading
- Aion-3.0 vs Aion-Mini: Benchmarks, Pricing & Speed ComparisonCompare
- Aion-3.0 vs Gemini 3.6 Flash: Benchmarks, Pricing & Speed ComparisonCompare
- Aion-Mini vs Laguna XS 2.1: Benchmarks, Pricing & Speed ComparisonCompare
- Aya Expanse 32B vs Llama 3.2 90B Vision: Benchmarks, Pricing & Speed ComparisonCompare
- Aya Expanse 8B vs Command R+: Benchmarks, Pricing & Speed ComparisonCompare
- Aya Expanse 8B vs Qwen 2.5 7B Instruct: Benchmarks, Pricing & Speed ComparisonCompare
Benchmark scores, token prices, and rate limits evolve rapidly as AI labs release model updates. Always verify current specifications and pricing on the official provider documentation.
Sources: Sakana AI & Anthropic Official Documentation