# Claude Fable 5.1 vs Ternary Bonsai 2 27B

> Side-by-side benchmark comparison for Claude Fable 5.1 and Ternary Bonsai 2 27B across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-5-1-vs-ternary-bonsai-2-27b
- Last updated: September 18, 2026

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

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for Claude Fable 5.1 and Ternary Bonsai 2 27B.

## Summary

- Claude Fable 5.1 and Ternary Bonsai 2 27B 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 | Claude Fable 5.1 | Ternary Bonsai 2 27B |
|----------|----------|----------|
| Creator | Anthropic | Prism ML |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 262K |
| Independent public score (not head-to-head) | 84.74 | 50.78 |
| Benchmarks Covered | 26 | 21 |
| Pricing (input/output) | $10.00 / $50.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 80.2 (Supported · #1/154)
- Ternary Bonsai 2 27B public-lane score: 49.9 (Estimated · #59/154)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 55.80% | Coming soon | Coming soon |
| Terminal-Bench-Science 0.1 | 52.6% | Coming soon | Coming soon |
| OSWorld 2.0 | 41.7% | Coming soon | Coming soon |
| AutomationBench | 31.4% | Coming soon | Coming soon |
| Toolathlon-Verified | 77.8% | Coming soon | Coming soon |
| Toolathlon Verified Pass@3 | 81.5% | Coming soon | Coming soon |
| Toolathlon Verified Pass³ | 73.1% | Coming soon | Coming soon |
| Toolathlon Verified avg. turns | 23.7 turns | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 85.0% | Coming soon | Coming soon |
| ApprenticeBench | 72% | Coming soon | Coming soon |
| τ²-bench results | Coming soon | 80.2% | Coming soon |
| BFCL v3 | Coming soon | 74.9% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 52.8% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 83.8 (Supported · #1/154)
- Ternary Bonsai 2 27B public-lane score: 49.9 (Estimated · #64/154)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43 fixes | Coming soon | Coming soon |
| SWE-bench Pro | 81.2% | Coming soon | Coming soon |
| SWE Multilingual | 89.1% | Coming soon | Coming soon |
| SWE Multimodal | 54.7% | Coming soon | Coming soon |
| DeepSWE | 67.4% | Coming soon | Coming soon |
| FrontierSWE v2 | 56.3% | Coming soon | Coming soon |
| ProgramBench | 87.6% | Coming soon | Coming soon |
| cursorBench32 | 73.4% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 90.5% | Coming soon | Coming soon |
| cursorBench40 | 51.8% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 90.1% | Coming soon |
| BigCodeBench | Coming soon | 58.1% | Coming soon |
| SWE-bench Verified | Coming soon | 60.8% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 52.8% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: Coming soon
- Ternary Bonsai 2 27B public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| CharXiv (overall) | Coming soon | 80.0% | Coming soon |
| A-OKVQA | Coming soon | 86.8% | Coming soon |
| OmniDocBench 1.6 | Coming soon | 89.1% | Coming soon |
| RealWorldQA | Coming soon | 80.1% | Coming soon |
| OCRBench V2 | Coming soon | 56.9% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 79.4 (#2/20)
- Ternary Bonsai 2 27B public-lane score: 73.9 (Unranked · 1 rankable row)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 97.50% | Coming soon | Coming soon |
| ARC-AGI-2 | 90% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 86.7 (Supported · #1/184)
- Ternary Bonsai 2 27B public-lane score: 50.6 (Estimated · #78/184)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| HLE | 65% | Coming soon | Coming soon |
| HLE w/o tools | 60.9% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 93.4% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 92.4% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 89.1% | Coming soon |
| GPQA | Coming soon | 85.8% | Coming soon |
| GPQA-D | Coming soon | 85.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: Coming soon
- Ternary Bonsai 2 27B public-lane score: 71 (#64/124)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 91.3% | Coming soon |
| IFBench | Coming soon | 74% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: Coming soon
- Ternary Bonsai 2 27B public-lane score: 76.8 (Unranked · 4 rankable rows)

| Benchmark | Claude Fable 5.1 | Ternary Bonsai 2 27B | Winner |
|-----------|-----------|-----------|--------|
| GSM8K | Coming soon | 96.7% | Coming soon |
| MATH-500 | Coming soon | 98.8% | Coming soon |
| AIME 2025 | Coming soon | 95% | Coming soon |
| AIME26 | Coming soon | 95.8% | Coming soon |

## FAQ

### Can I compare Claude Fable 5.1 and Ternary Bonsai 2 27B 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

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [Ternary Bonsai 2 27B vs Claude Fable 5](/compare/claude-fable-vs-ternary-bonsai-2-27b)
- [Claude Fable 5.1 vs GPT-6 Astra](/compare/claude-fable-5-1-vs-gpt-6-astra)
- [Ternary Bonsai 2 27B vs GPT-6 Astra](/compare/gpt-6-astra-vs-ternary-bonsai-2-27b)

## Explore More

- [Claude Fable 5.1 profile](/models/claude-fable-5-1)
- [Ternary Bonsai 2 27B profile](/models/ternary-bonsai-2-27b)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)