# Claude Fable 5.1 vs Composer 2.5

> Side-by-side benchmark comparison for Claude Fable 5.1 and Composer 2.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-5-1-vs-composer-2-5
- Last updated: October 17, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick Claude Fable 5.1 if you want the stronger benchmark profile. Composer 2.5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Fable 5.1 leads overall 83.18 to 64.
- The biggest single benchmark swing is Terminal-Bench 2.1 (Vals) in Agentic, with scores of 85.0% and 58.4%.
- Composer 2.5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Claude Fable 5.1 also has the larger context window at 1M.

## Model Snapshot

| Property | Claude Fable 5.1 | Composer 2.5 |
|----------|----------|----------|
| Creator | Anthropic | Cursor |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 200K |
| Overall Score | 83.18 | null |
| Benchmarks Covered | 33 | 8 |
| Pricing (input/output) | $10.00 / $50.00 | $0.50 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | 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% | 58.4% | Claude Fable 5.1 |
| ApprenticeBench | 72% | Coming soon | Coming soon |
| CWE-bench v1 | 58.0% | Coming soon | Coming soon |
| MazeBench | 10% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 69.3% | Coming soon |

### Coding

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43.0 fixes | Coming soon | Coming soon |
| SWE-bench Pro | 81.2% | Coming soon | Coming soon |
| SWE Multilingual | 89.1% | 79.8% | Claude Fable 5.1 |
| 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 |
| CursorBench 3.2 | 73.4% | 56.1% | Claude Fable 5.1 |
| LiveCodeBench (Vals) | 90.5% | Coming soon | Coming soon |
| CursorBench 4.0 | 51.8% | 27.7% | Claude Fable 5.1 |
| PostTrainBench v1.1 | 40.2% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | Coming soon | 69.3% | Coming soon |
| cursorBench31 | Coming soon | 63.2% | Coming soon |
| SWE-bench (Vals) | Coming soon | 79.6% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 97.50% | Coming soon | Coming soon |
| ARC-AGI-2 | 90% | Coming soon | Coming soon |
| GraphWalks BFS 256K–1M | 65.0% | Coming soon | Coming soon |

### Knowledge

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | 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 |

### Instruction Following

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 1.0% | Coming soon | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)
- Composer 2.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Composer 2.5 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 90.175% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 87.805% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Fable 5.1 or Composer 2.5?

Claude Fable 5.1 is ahead overall on BenchLM right now.

### How many benchmarks does Claude Fable 5.1 cover on BenchLM?

Claude Fable 5.1 currently has 33 sourced benchmark scores on BenchLM.

### How many benchmarks does Composer 2.5 cover on BenchLM?

Composer 2.5 currently has 8 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [Composer 2.5 vs Claude Fable 5](/compare/claude-fable-vs-composer-2-5)
- [Claude Fable 5.1 vs Composer 2](/compare/claude-fable-5-1-vs-composer-2)
- [Composer 2.5 vs Composer 2](/compare/composer-2-vs-composer-2-5)

## Explore More

- [Claude Fable 5.1 profile](/models/claude-fable-5-1)
- [Composer 2.5 profile](/models/composer-2-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)