# BTL-4 vs Claude Fable 5.1

> Side-by-side benchmark comparison for BTL-4 and Claude Fable 5.1 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/btl-4-vs-claude-fable-5-1
- Last updated: October 17, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for BTL-4 and Claude Fable 5.1.

## Summary

- BTL-4 and Claude Fable 5.1 do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | BTL-4 | Claude Fable 5.1 |
|----------|----------|----------|
| Creator | Bad Theory Labs | Anthropic |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 262K | 1M |
| Independent public score (not head-to-head) | null | 83.18 |
| Benchmarks Covered | 3 | 33 |
| Pricing (input/output) | $0.00 / $0.00 | $10.00 / $50.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | 73.5% | Coming soon | Coming soon |
| Terminal-Bench 4.0 | Coming soon | 55.80% | Coming soon |
| Terminal-Bench-Science 0.1 | Coming soon | 52.6% | Coming soon |
| OSWorld 2.0 | Coming soon | 41.7% | Coming soon |
| AutomationBench | Coming soon | 31.4% | Coming soon |
| Toolathlon-Verified | Coming soon | 77.8% | Coming soon |
| Toolathlon Verified Pass@3 | Coming soon | 81.5% | Coming soon |
| Toolathlon Verified Pass³ | Coming soon | 73.1% | Coming soon |
| Toolathlon Verified avg. turns | Coming soon | 23.7 turns | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 85.0% | Coming soon |
| ApprenticeBench | Coming soon | 72% | Coming soon |
| CWE-bench v1 | Coming soon | 58.0% | Coming soon |
| MazeBench | Coming soon | 10% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 78.4% | Coming soon | Coming soon |
| LiveCodeBench v6 | 66.1% | Coming soon | Coming soon |
| Bug Hunt Bench | Coming soon | 43.0 fixes | Coming soon |
| SWE-bench Pro | Coming soon | 81.2% | Coming soon |
| SWE Multilingual | Coming soon | 89.1% | Coming soon |
| SWE Multimodal | Coming soon | 54.7% | Coming soon |
| DeepSWE | Coming soon | 67.4% | Coming soon |
| FrontierSWE v2 | Coming soon | 56.3% | Coming soon |
| ProgramBench | Coming soon | 87.6% | Coming soon |
| CursorBench 3.2 | Coming soon | 73.4% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 90.5% | Coming soon |
| CursorBench 4.0 | Coming soon | 51.8% | Coming soon |
| PostTrainBench v1.1 | Coming soon | 40.2% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | Coming soon | 97.50% | Coming soon |
| ARC-AGI-2 | Coming soon | 90% | Coming soon |
| GraphWalks BFS 256K–1M | Coming soon | 65.0% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| HLE | Coming soon | 65% | Coming soon |
| HLE w/o tools | Coming soon | 60.9% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 93.4% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 92.4% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: Coming soon

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | Coming soon | 1.0% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- BTL-4 public-lane score: Coming soon
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)

| Benchmark | BTL-4 | Claude Fable 5.1 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | Coming soon | 90.175% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 87.805% | Coming soon |

## FAQ

### Can I compare BTL-4 and Claude Fable 5.1 on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [BTL-4 vs BTL-3](/compare/btl-3-vs-btl-4)
- [Claude Fable 5.1 vs BTL-3](/compare/btl-3-vs-claude-fable-5-1)
- [BTL-4 vs BTL-4 Compact](/compare/btl-4-vs-btl-4-compact)
- [Claude Fable 5.1 vs BTL-4 Compact](/compare/btl-4-compact-vs-claude-fable-5-1)

## Explore More

- [BTL-4 profile](/models/btl-4)
- [Claude Fable 5.1 profile](/models/claude-fable-5-1)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)