# BTL-4 vs Sakana Fugu-Ultra

> Side-by-side benchmark comparison for BTL-4 and Sakana Fugu-Ultra across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/btl-4-vs-sakana-fugu-ultra
- Last updated: September 24, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Evidence is too thin for a benchmark verdict: BTL-4 and Sakana Fugu-Ultra share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Sakana Fugu-Ultra has the lower published output-token price.
- Sakana Fugu-Ultra has the larger published context window at 1M.

## Model Snapshot

| Property | BTL-4 | Sakana Fugu-Ultra |
|----------|----------|----------|
| Creator | Bad Theory Labs | Sakana AI |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 262K | 1M |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 3 | 11 |
| Pricing (input/output) | $0.00 / $0.00 | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Sakana Fugu-Ultra public-lane score: Coming soon

| Benchmark | BTL-4 | Sakana Fugu-Ultra | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | 73.5% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 82.1% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Sakana Fugu-Ultra public-lane score: Coming soon

| Benchmark | BTL-4 | Sakana Fugu-Ultra | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 78.4% | Coming soon | Coming soon |
| LiveCodeBench v6 | 66.1% | 93.2% | Sakana Fugu-Ultra |
| SWE-bench Pro | Coming soon | 73.7% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 82.1% | Coming soon |
| LiveCodeBench Pro | Coming soon | 90.8% | Coming soon |
| SciCode | Coming soon | 58.7% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Sakana Fugu-Ultra public-lane score: 79 (Unranked · 1 rankable row)

| Benchmark | BTL-4 | Sakana Fugu-Ultra | Winner |
|-----------|-----------|-----------|--------|
| MRCRv2 | Coming soon | 93.6% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Sakana Fugu-Ultra public-lane score: 72.6 (Unranked · 1 rankable row)

| Benchmark | BTL-4 | Sakana Fugu-Ultra | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 86.6% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Sakana Fugu-Ultra public-lane score: Coming soon

| Benchmark | BTL-4 | Sakana Fugu-Ultra | Winner |
|-----------|-----------|-----------|--------|
| GPQA | Coming soon | 95.5% | Coming soon |
| GPQA-D | Coming soon | 95.5% | Coming soon |
| HLE w/o tools | Coming soon | 50% | Coming soon |

## FAQ

### Is there enough evidence to pick between BTL-4 and Sakana Fugu-Ultra?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [BTL-4 vs BTL-3](/compare/btl-3-vs-btl-4)
- [Sakana Fugu-Ultra vs BTL-3](/compare/btl-3-vs-sakana-fugu-ultra)
- [BTL-4 vs BTL-4 Compact](/compare/btl-4-vs-btl-4-compact)
- [Sakana Fugu-Ultra vs BTL-4 Compact](/compare/btl-4-compact-vs-sakana-fugu-ultra)

## Explore More

- [BTL-4 profile](/models/btl-4)
- [Sakana Fugu-Ultra profile](/models/sakana-fugu-ultra)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)