Head-to-Head Model Comparison

Fugu Ultra vs GPT-6.1 Sol

Benchmarks, API Token Pricing, Context Window & Speed Comparison

Reviewed by the GetInfoUs research teamLast reviewed: October 2026Editorial policy
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Compare Fugu Ultra by Sakana AI against GPT-6.1 Sol by OpenAI across real-world coding, reasoning, token economics, and latency.

Head-to-Head Comparison

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Live comparison: no in-depth editorial review has been published for this pair yet.

Popular Matchups:
Sakana AI

Fugu Ultra

Premium Reasoner

Sakana AI's Japanese-multilingual frontier reasoning model developed using evolutionary model merging with million-token capacity.

Intelligence Index86 / 100
Input Token:

$1.50 / 1M

Output Token:

$6.00 / 1M

Context Window:

1M tokens

SWE-bench Verified:

N/A

OpenAI

GPT-6.1 Sol

Near-Astra Value

Delivers results close to GPT-6 Astra at roughly one fifth of the price — the latest 2026 release.

Intelligence Index94 / 100
Input Token:

$2.00 / 1M

Output Token:

$10.00 / 1M

Context Window:

1M tokens

SWE-bench Verified:

82.3%

Key Differences at a Glance

  • Fugu Ultra is 1.5x cheaper for API usage (input + output tokens combined).
  • GPT-6.1 Sol is faster at 120 tok/s vs 75 tok/s.
Need definitions for token pricing, context, or benchmarks?Explore AI Glossary →
FeatureFugu UltraGPT-6.1 Sol
Intelligence Index
Composite reasoning & knowledge score (0-100)
8694
Provider
Sakana AIOpenAI
Input Price
Cost per million input tokens
$1.50 / 1M$2.00 / 1M
Output Price
Cost per million output tokens
$6.00 / 1M$10.00 / 1M
Blended Price
Weighted 7:2:1 cache:input:output per 1M
$1.01 / 1M$1.47 / 1M
Context Window
Maximum input + output tokens
1M tokens~1,500 A4 pages of text1M tokens~1,500 A4 pages of text
Max Output Tokens
Per single request
16K128K
Throughput Speed
Tokens generated per second
75 tok/s120 tok/s
SWE-bench Verified
Real-world software engineering
N/A82.3%
GPQA Diamond
Graduate-level reasoning
67%80.8%
Cached Input Price
Prompt caching discount per 1M tokens
$0.15 / 1M$0.10 / 1M

Who Wins Where?

At-a-glance decision framework
Coding

Evaluations ongoing

Cost
Fugu Ultra
1.5x cheaper monthly runtime
Speed
GPT-6.1 Sol
+60% faster generation
Context
Tied
1M tokens window

Empirical Head-to-Head Benchmark Scores

Official evaluation metrics verified by independent third-party research labs.

Fugu UltraGPT-6.1 Sol
SWE-bench Verified (Autonomous Coding)

Industry benchmark evaluating real-world GitHub issue resolution and multi-file debugging.

N/Avs82.3%
GPQA Diamond (Doctorate-Level Science & Math)

Challenging questions created by domain experts to test complex PhD-level reasoning.

67%vs80.8%
MMLU-Pro (Multi-task Language Understanding)

Hardened reasoning and academic knowledge benchmark with reduced lucky-guess probability.

83%vs89.9%
LMSYS Chatbot Arena Elo

Crowdsourced human preference evaluation based on blind, head-to-head model battles.

1370ptsvs1519pts
Humanity's Last Exam (Frontier Expert Knowledge)

Extremely difficult, closed-ended questions spanning the frontier of human expert knowledge.

N/Avs18.1%
Terminal-Bench (Agentic Coding & Terminal Use)

Autonomous multi-step tasks executed inside a real command-line terminal environment.

N/Avs63.6%
SciCode (Scientific Computing)

Research-grade coding problems drawn from real scientific and numerical workloads.

N/Avs54.8%
LiveCodeBench (Competitive Coding)

Contamination-free competitive programming problems collected continuously over time.

N/Avs79.7%
AIME (Advanced Math Competition)

American Invitational Mathematics Examination — multi-step Olympiad-level reasoning.

N/Avs93.5%
Long-Context Reasoning

Accuracy when reasoning over very large inputs that fill the model context window.

N/Avs91%
Generation Speed (Throughput)

Tokens emitted per second during active generation streaming.

75 tok/s vs120 tok/s

Latency & Response Time

Time to first token (TTFT) and estimated end-to-end response time for a typical 500-token response.

Time to First Token (TTFT)Lower is better
Fugu Ultra0.54s
GPT-6.1 Sol1.12s
Est. End-to-End Response (500 tokens)TTFT + generation time
Fugu Ultra7.21s
GPT-6.1 Sol5.29s

Real-Time Interactive Token Cost Simulator

Adjust sliders to calculate projected monthly cloud API spending with prompt caching discounts.

100K / day
10K500K1M
30K / day
5K150K300K
50% cached
0% (Cold)50%90% (Warm)
Fugu Ultra Monthly API Bill
$7.88 / month
$1.5/1M in · $6/1M out
GPT-6.1 Sol Monthly API Bill
$12.15 / month
$2/1M in · $10/1M out
Fugu Ultra saves approximately $4.28 / month (35%) under this workload.1.5x Savings

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

GPT-6.1 Sol · Strengths & Key Advantages

  • Near-Astra results at roughly a fifth of the cost
  • Excellent coding and long-horizon agent performance
  • Strong reliability with far lower latency than Astra
  • Near-flagship results at roughly a fifth of the price
Considerations & Trade-offs
  • Still marginally behind Astra on the very hardest reasoning
  • Same price as GPT-6 Sol, so the upgrade decision is easy

Token Use & Task Economics

Estimated cost and token consumption to complete one representative agentic task.

MetricFugu UltraGPT-6.1 Sol
Cost per Task
Estimated USD to finish one task
$0.28$2.05
Output Tokens / Task
Tokens generated per task
22K62K
Reasoning Tokens / Task
Thinking tokens burned per task
8K36K

Technical Specifications

Architecture, release timeline, capabilities, and modalities.

FeatureFugu UltraGPT-6.1 Sol
Official API Model ID (SDK)fugu-ultragpt-6-1-sol
API ProtocolSakana AI REST API (OpenAI-Compatible)OpenAI Responses API & Chat Completions v1
Release Date2026-062026-09
Knowledge CutoffMarch 2026April 2026
ArchitectureEvolutionary Multi-Model Merged TransformerNear-Astra unified reasoning model
ParametersConfidential / Frontier MergedConfidential
Enterprise Rate Limits (RPM / TPM)5,000 – 15,000 RPM (Production Tier) · 4,000,000 – 10,000,000 TPM10,000 – 30,000 RPM (Tier 5 Enterprise) · 4,000,000 – 10,000,000 TPM
Long-Context Tier (>128K/200K)Flat rate ($1.5/1M in) across full 1000K windowFlat rate ($2/1M in) across full 1000K window
Prompt Cache Policy & TTLCached input at $0.15/1M tokensAutomatic prefix caching at $0.1/1M (no extra cache-write fee)
Computer Use / GUI AgentAPI / CLI Tool-Use & DOM Agent ready (no raw pixel desktop click loop)Supported (Screen coordinate grounding, browser & desktop GUI action loops)
MCP & Parallel Tool CallingNative MCP Client/Server ready · Parallel function calling · 100% Strict JSON SchemaNative MCP Client/Server ready · Parallel function calling · 100% Strict JSON Schema
Web Search Grounding & SandboxSupported via external Tavily/Exa Search & E2B/Docker Sandbox toolsNative Web Search tool + Hosted Code Interpreter & File Search RAG
Official Fine-Tuning SupportAPI Prompt Engineering & RAG DistillationSupervised Fine-Tuning (SFT), Direct Preference (DPO) & Reinforcement Fine-Tuning (RFT)
Multimodal Token BillingText BPE (~4 chars/token)Text BPE (~4 chars/token) · Vision (~258–765 tokens per image tile)
Quantization & Min GPU VRAMCloud-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 ClassificationSakana AI Production Safety & Alignment VerifiedOpenAI Preparedness Framework Audited & System Card Published
Enterprise Compliance (ZDR/HIPAA/SOC2)SOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise TierSOC2 Type II · GDPR · Zero Data Retention (ZDR) & HIPAA BAA Available on Enterprise Tier
Input Modalitiestexttext, vision
Output Modalitiestexttext

Fugu Ultra vs GPT-6.1 Sol: Quick Answers

Which is more intelligent, Fugu Ultra or GPT-6.1 Sol?

GPT-6.1 Sol is more intelligent. It scores 94 compared with 86 on the composite Intelligence Index.

Which model is faster?

GPT-6.1 Sol is faster, generating 120 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 $1.47 (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 1.12s.

Verdict

Choose Fugu Ultra for japanese enterprise intelligence, bilingual translation, and creative scientific exploration, or choose GPT-6.1 Sol for the best value frontier model for professional and agentic work.

Frequently asked questions

Which is cheaper: Fugu Ultra or GPT-6.1 Sol?+

Fugu Ultra costs $1.5/1M input and $6/1M output tokens, while GPT-6.1 Sol costs $2/1M input and $10/1M output tokens.

Which model has a larger context window: Fugu Ultra or GPT-6.1 Sol?+

Fugu Ultra supports 1M tokens whereas GPT-6.1 Sol supports 1M tokens.

AI Terminology & Guide
Explore Glossary →

Understand key metrics like context window, token pricing, reasoning mode, and SWE-bench scores in our comprehensive AI glossary.

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 & OpenAI Official Documentation