# BTL-4 vs Claude Sonnet 5

> Side-by-side benchmark comparison for BTL-4 and Claude Sonnet 5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/btl-4-vs-claude-sonnet-5
- Last updated: September 21, 2026

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

## Quick Verdict

Evidence is too thin for a benchmark verdict: BTL-4 and Claude Sonnet 5 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.
- BTL-4 has the lower published output-token price.
- Claude Sonnet 5 has the larger published context window at 1M.

## Model Snapshot

| Property | BTL-4 | Claude Sonnet 5 |
|----------|----------|----------|
| Creator | Bad Theory Labs | Anthropic |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 262K | 1M |
| Independent public score (not head-to-head) | null | 69.56 |
| Benchmarks Covered | 3 | 26 |
| Pricing (input/output) | $0.00 / $0.00 | $2.00 / $10.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: 50.5 (Estimated · #50/154)
- Claude Sonnet 5 public-lane score: 66.2 (Supported · #11/154)

| Benchmark | BTL-4 | Claude Sonnet 5 | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | 73.5% | Coming soon | Coming soon |
| Terminal-Bench 3.0 | Coming soon | 14.6% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 80.4% | Coming soon |
| BrowseComp | Coming soon | 84.7% | Coming soon |
| HLE w/ tools | Coming soon | 57.4% | Coming soon |
| OSWorld-Verified | Coming soon | 81.2% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 74.5% | Coming soon |
| ApprenticeBench | Coming soon | 16% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: 50.4 (Estimated · #62/156)
- Claude Sonnet 5 public-lane score: 64.6 (Supported · #13/156)

| Benchmark | BTL-4 | Claude Sonnet 5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 78.4% | 85.2% | Claude Sonnet 5 |
| LiveCodeBench v6 | 66.1% | Coming soon | Coming soon |
| SWE-bench Pro | Coming soon | 63.2% | Coming soon |
| SWE Multilingual | Coming soon | 78.3% | Coming soon |
| SWE Multimodal | Coming soon | 28.1% | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 80.4% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 42.7% | Coming soon |
| cursorBench32 | Coming soon | 61.5% | Coming soon |
| VulcanBench CII v1 | Coming soon | 89.2% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 82.4% | Coming soon |
| SWE-bench (Vals) | Coming soon | 79.6% | Coming soon |
| cursorBench40 | Coming soon | 34.1% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Sonnet 5 public-lane score: 77.4 (Unranked · 2 rankable rows)

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Sonnet 5 public-lane score: 77.4 (#14/49)

| Benchmark | BTL-4 | Claude Sonnet 5 | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 88.3% | Coming soon |
| CharXiv w/o tools | Coming soon | 77% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Sonnet 5 public-lane score: 66.8 (Supported · #20/186)

| Benchmark | BTL-4 | Claude Sonnet 5 | Winner |
|-----------|-----------|-----------|--------|
| HLE | Coming soon | 57.4% | Coming soon |
| HLE w/o tools | Coming soon | 43.2% | Coming soon |
| HLE-Verified | Coming soon | 31.0% | Coming soon |
| LABBench2 | Coming soon | 80.1% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 88.9% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 87.5% | Coming soon |

## FAQ

### Is there enough evidence to pick between BTL-4 and Claude Sonnet 5?

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)
- [Claude Sonnet 5 vs BTL-3](/compare/btl-3-vs-claude-sonnet-5)
- [BTL-4 vs BTL-4 Compact](/compare/btl-4-vs-btl-4-compact)
- [Claude Sonnet 5 vs BTL-4 Compact](/compare/btl-4-compact-vs-claude-sonnet-5)

## Explore More

- [BTL-4 profile](/models/btl-4)
- [Claude Sonnet 5 profile](/models/claude-sonnet-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)