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Model comparison

Claude Opus 4.8 vs Sakana Fugu-Ultra

Data verified

Head-to-head evidence from 7 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

78.34/100
No comparison
N/A
1 category wins3 category wins

Public leaderboard positions: Claude Opus 4.8 #5 (Supported); Sakana Fugu-Ultra unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Opus 4.8 and Sakana Fugu-Ultra share 7 comparable benchmark results. 4 of 8 categories are comparable. 46 results are unique to Claude Opus 4.8; 4 to Sakana Fugu-Ultra.

Updated July 23, 2026
Shared results
7
Claude Opus 4.8 only
46
Sakana Fugu-Ultra only
4
Comparable categories
4 / 8

Treat this as a split decision. Claude Opus 4.8 makes more sense if coding is the priority; Sakana Fugu-Ultra is the better fit if knowledge is the priority.

Confidence note. This is a partial-evidence comparison with 7 shared benchmark results across 4 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Claude Opus 4.8 and Sakana Fugu-Ultra finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Opus 4.8 and Sakana Fugu-Ultra
CategoryClaude Opus 4.8ΔSakana Fugu-Ultra
KnowledgeClaude Opus 4.862.7Margin→ 32.8Sakana Fugu-Ultra95.5
CodingClaude Opus 4.881.1Margin← 16.6Sakana Fugu-Ultra64.5
MultimodalClaude Opus 4.877.0Margin→ 9.6Sakana Fugu-Ultra86.6
AgenticClaude Opus 4.880.3Margin→ 1.8Sakana Fugu-Ultra82.1
ReasoningClaude Opus 4.8Not measuredMarginNo overlapSakana Fugu-Ultra93.6
MathClaude Opus 4.853.9MarginNo overlapSakana Fugu-UltraNot measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Opus 4.8B · Sakana Fugu-Ultra

  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 74.6%B 82.1%
    Winner: Sakana Fugu-UltraΔ 7.5
    Terminal-Bench 2.0: Claude Opus 4.8 scored 74.6%; Sakana Fugu-Ultra scored 82.1%. Sakana Fugu-Ultra wins this benchmark.

  2. SWE-bench Pro

    Coding
    Source ↗
    A 69.2%B 73.7%
    Winner: Sakana Fugu-UltraΔ 4.5
    SWE-bench Pro: Claude Opus 4.8 scored 69.2%; Sakana Fugu-Ultra scored 73.7%. Sakana Fugu-Ultra wins this benchmark.

  3. CharXiv

    Multimodal
    Source ↗
    A 89.9%B 86.6%
    Winner: Claude Opus 4.8Δ 3.3
    CharXiv: Claude Opus 4.8 scored 89.9%; Sakana Fugu-Ultra scored 86.6%. Claude Opus 4.8 wins this benchmark.

  4. GPQA

    Knowledge
    Source ↗
    A 93.6%B 95.5%
    Winner: Sakana Fugu-UltraΔ 1.9
    GPQA: Claude Opus 4.8 scored 93.6%; Sakana Fugu-Ultra scored 95.5%. Sakana Fugu-Ultra wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Opus 4.8Sakana Fugu-UltraComparison
Input / output priceUSD per 1M tokensClaude Opus 4.8$5 input / $25 outputSakana Fugu-UltraNot availableA complete price comparison is not available.
Generation speedtokens per secondClaude Opus 4.8Not availableSakana Fugu-UltraNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Opus 4.8Not availableSakana Fugu-UltraNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Opus 4.81MSakana Fugu-Ultra1MListed context windows are equal.

Benchmark Deep Dive

AgenticSakana Fugu-Ultra wins
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
Terminal-Bench 2.0Source 74.6%82.1%Sakana Fugu-Ultra leads
BrowseCompSource 84.3%—Not comparable
DeepSearchQASource 93.1%—Not comparable
OSWorld-VerifiedSource 83.4%—Not comparable
Finance Agent v2Source 53.9%—Not comparable
GDPval-AASource 1594—Not comparable
MCP AtlasSource 82.2%—Not comparable
ToolathlonSource 59.9%—Not comparable
Gert LabsSource 72.97%—Not comparable
AA Agentic IndexSource 47.2%—Not comparable
τ²-bench resultsSource 94.4%—Not comparable
GDPval-AASource 54.7%—Not comparable
ResearchClawBenchSource 21.1%—Not comparable
OSWorld 2.0Source 20.6%—Not comparable
AA BriefcaseSource 1347—Not comparable
AA AutomationBenchSource 48.5%—Not comparable
AA EnterpriseOps-GymSource 44.0%—Not comparable
AA Harvey LABSource 91.1%—Not comparable
AA Tau3 BankingSource 27.6%—Not comparable
terminalBenchHardSource 58.3%—Not comparable
aaTerminalBench21Source 84.6%—Not comparable
CodingClaude Opus 4.8 wins
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
SWE-bench VerifiedSource 88.6%—Not comparable
SWE-bench ProSource 69.2%73.7%Sakana Fugu-Ultra leads
SWE MultilingualSource 84.4%—Not comparable
SWE MultimodalSource 38.4%—Not comparable
Terminal-Bench 2.0Source 74.6%82.1%Sakana Fugu-Ultra leads
cursorBench31Source 58.4%—Not comparable
cursorBench32Source 62.3%—Not comparable
AA Coding IndexSource 74.3%—Not comparable
AA-SciCodeSource 53.5%—Not comparable
FrontierCode 1.1 MainSource 46.5%—Not comparable
LiveCodeBench v6Source —93.2%Not comparable
LiveCodeBench ProSource —90.8%Not comparable
SciCodeSource —58.7%Not comparable
Reasoning
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
AA-LCRSource 67.7%—Not comparable
CritPtSource 20.9%—Not comparable
MRCRv2Source —93.6%Not comparable
KnowledgeSakana Fugu-Ultra wins
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
GPQASource 93.6%95.5%Sakana Fugu-Ultra leads
GPQA-DSource 93.6%95.5%Sakana Fugu-Ultra leads
HLESource 57.9%—Not comparable
HLE w/o toolsSource 49.8%50%Sakana Fugu-Ultra leads
Artificial Analysis Intelligence IndexSource 55.7%—Not comparable
AA-GPQA DiamondSource 92.0%—Not comparable
AA-HLESource 45.7%—Not comparable
AA-Omniscience IndexSource 27.4%—Not comparable
AA-Omniscience AccuracySource 46.6%—Not comparable
AA-Omniscience Hallucination RateSource 35.9%—Not comparable
Math
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
USAMO 2026Source 96.7%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 47.241%—Not comparable
FrontierMath v2 (Tier 4)Source 31.250%—Not comparable
Multilingual
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
INCLUDESource 87.6%—Not comparable
MultimodalSakana Fugu-Ultra wins
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
OfficeQA ProSource 66.2%—Not comparable
ScreenSpot ProSource 87.9%—Not comparable
CharXivSource 89.9%86.6%Claude Opus 4.8 leads
CharXiv w/o toolsSource 80.5%—Not comparable
Design Arena WebsiteSource 1270—Not comparable
Inst. Following
BenchmarkClaude Opus 4.8Sakana Fugu-UltraResult
AA-IFBenchSource 62.2%—Not comparable
Frequently Asked Questions (5)

Which is better, Claude Opus 4.8 or Sakana Fugu-Ultra?

Claude Opus 4.8 and Sakana Fugu-Ultra are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.

Which is better for knowledge tasks, Claude Opus 4.8 or Sakana Fugu-Ultra?

Sakana Fugu-Ultra has the edge for knowledge tasks in this comparison, averaging 95.5 versus 62.7. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Claude Opus 4.8 or Sakana Fugu-Ultra?

Claude Opus 4.8 has the edge for coding in this comparison, averaging 81.1 versus 64.5. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Claude Opus 4.8 or Sakana Fugu-Ultra?

Sakana Fugu-Ultra has the edge for agentic tasks in this comparison, averaging 82.1 versus 80.3. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Claude Opus 4.8 or Sakana Fugu-Ultra?

Sakana Fugu-Ultra has the edge for multimodal and grounded tasks in this comparison, averaging 86.6 versus 77. Inside this category, CharXiv is the benchmark that creates the most daylight between them.

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