Model comparison
Claude 4 Sonnet vs Sakana Fugu-Ultra
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Claude 4 Sonnet #158 (Supported); Sakana Fugu-Ultra unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Claude 4 Sonnet and Sakana Fugu-Ultra share 0 comparable benchmark results. 1 of 8 categories are comparable. 16 results are unique to Claude 4 Sonnet; 11 to Sakana Fugu-Ultra.
Updated July 23, 2026- Shared results
- 0
- Claude 4 Sonnet only
- 16
- Sakana Fugu-Ultra only
- 11
- Comparable categories
- 1 / 8
Treat this as a split decision. Claude 4 Sonnet makes more sense if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model; Sakana Fugu-Ultra is the better fit if you need the larger 1M context window or you want the stronger reasoning-first profile.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
Claude 4 Sonnet 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.
Sakana Fugu-Ultra is the reasoning model in the pair, while Claude 4 Sonnet is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Sakana Fugu-Ultra gives you the larger context window at 1M, compared with 200K for Claude 4 Sonnet.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude 4 Sonnet | Sakana Fugu-Ultra | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude 4 Sonnet$3 input / $15 output | Sakana Fugu-UltraNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Claude 4 Sonnet40 tok/s | Sakana Fugu-UltraNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude 4 Sonnet1.33 s | Sakana Fugu-UltraNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude 4 Sonnet200K | Sakana Fugu-Ultra1M | Sakana Fugu-Ultra lists the larger context window. |
Benchmark Deep Dive
Agentic4 benchmarks
CodingClaude 4 Sonnet wins7 benchmarks
| Benchmark | Claude 4 Sonnet | Sakana Fugu-Ultra | Result |
|---|---|---|---|
| SWE-bench VerifiedSource | 72.7% | — | Not comparable |
| AA-SciCodeSource | 37.3% | — | Not comparable |
| SWE-bench ProSource | — | 73.7% | Not comparable |
| Terminal-Bench 2.0Source | — | 82.1% | Not comparable |
| LiveCodeBench v6Source | — | 93.2% | Not comparable |
| LiveCodeBench ProSource | — | 90.8% | Not comparable |
| SciCodeSource | — | 58.7% | Not comparable |
Reasoning3 benchmarks
Knowledge9 benchmarks
| Benchmark | Claude 4 Sonnet | Sakana Fugu-Ultra | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | 25.5% | — | Not comparable |
| AA-GPQA DiamondSource | 68.3% | — | Not comparable |
| AA-HLESource | 4.0% | — | Not comparable |
| AA-Omniscience IndexSource | -9.2% | — | Not comparable |
| AA-Omniscience AccuracySource | 22.4% | — | Not comparable |
| AA-Omniscience Hallucination RateSource | 40.8% | — | Not comparable |
| GPQASource | — | 95.5% | Not comparable |
| GPQA-DSource | — | 95.5% | Not comparable |
| HLE w/o toolsSource | — | 50% | Not comparable |
Multimodal3 benchmarks
Inst. Following1 benchmarks
| Benchmark | Claude 4 Sonnet | Sakana Fugu-Ultra | Result |
|---|---|---|---|
| AA-IFBenchSource | 45.4% | — | Not comparable |
Frequently Asked Questions (2)
Which is better, Claude 4 Sonnet or Sakana Fugu-Ultra?
Claude 4 Sonnet 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 coding, Claude 4 Sonnet or Sakana Fugu-Ultra?
Claude 4 Sonnet has the edge for coding in this comparison, averaging 72.7 versus 64.5. Sakana Fugu-Ultra stays close enough that the answer can still flip depending on your workload.
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