# Claude Fable 5 vs Claude Sonnet 5.5

> Side-by-side benchmark comparison for Claude Fable 5 and Claude Sonnet 5.5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-vs-claude-sonnet-5-5
- Last updated: September 28, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Pick Claude Sonnet 5.5 if you want the stronger benchmark profile. Claude Fable 5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Sonnet 5.5 leads overall 80.49 to 78.89.
- The clearest category separation is in multimodal & grounded, where the averages are 62.6 for Claude Fable 5 and 83.3 for Claude Sonnet 5.5.
- The biggest single benchmark swing is FrontierSWE v2 in Coding, with scores of 47.0% and 61.9%.
- Claude Sonnet 5.5 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Fable 5 | Claude Sonnet 5.5 |
|----------|----------|----------|
| Creator | Anthropic | Anthropic |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 1M |
| Overall Score | 78.89 | 80.49 |
| Benchmarks Covered | 21 | 47 |
| Pricing (input/output) | $10.00 / $50.00 | $2.00 / $10.00 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 73.8 (Supported · #4/111)
- Claude Sonnet 5.5 public-lane score: 66.1 (Supported · #10/111)

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 34.0% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 84.3% | Coming soon | Coming soon |
| OSWorld-Verified | 85% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 80.5% | Coming soon | Coming soon |
| ApprenticeBench | 34% | Coming soon | Coming soon |
| Terminal-Bench 4.0 | Coming soon | 70.60% | Coming soon |
| HLE w/ tools | Coming soon | 64.5% | Coming soon |
| DRACO | Coming soon | 87.0% | Coming soon |
| Terminal-Bench-Science 0.1 | Coming soon | 59.9% | Coming soon |
| LAB all-pass (Harvey held-out) | Coming soon | 10.0% | Coming soon |
| LAB criterion-pass (Harvey held-out) | Coming soon | 93.1% | Coming soon |
| Toolathlon Verified Pass@3 | Coming soon | 85.2% | Coming soon |
| Toolathlon Verified Pass³ | Coming soon | 68.5% | Coming soon |
| Toolathlon Verified avg. turns | Coming soon | 31.6 turns | Coming soon |
| AutomationBench (Zapier 1.0.6) | Coming soon | 44.7% | Coming soon |
| Toolathlon-Verified | Coming soon | 77.8% | Coming soon |

### Coding

- Winner: Directional only
- Claude Fable 5 public-lane score: 72.9 (Supported · #5/136)
- Claude Sonnet 5.5 public-lane score: 79.6 (Estimated · #3/136)

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 95% | Coming soon | Coming soon |
| SWE-bench Pro | 80% | 81.3% | Claude Sonnet 5.5 |
| FrontierSWE v2 | 47.0% | 61.9% | Claude Sonnet 5.5 |
| FrontierCode 1.1 Main | 53.5% | 46.2% | Claude Fable 5 |
| Terminal-Bench 2.1 | 84.3% | Coming soon | Coming soon |
| cursorBench31 | 70.6% | Coming soon | Coming soon |
| cursorBench32 | 70.5% | Coming soon | Coming soon |
| VulcanBench v3 | 89.5% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 89.8% | Coming soon | Coming soon |
| SWE-bench (Vals) | 95.0% | Coming soon | Coming soon |
| cursorBench40 | Coming soon | 55.5% | Coming soon |
| SWE Multilingual | Coming soon | 90.3% | Coming soon |
| SWE Multimodal | Coming soon | 54.3% | Coming soon |
| DeepSWE | Coming soon | 71.0% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 59.1% | Coming soon |
| ProgramBench | Coming soon | 79.7% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Fable 5 public-lane score: 80.7 (Unranked · 4 rankable rows)
- Claude Sonnet 5.5 public-lane score: 79.2 (#7/27)

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 98.50% | Coming soon | Coming soon |
| ARC-AGI-2 | 89.2% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Fable 5 public-lane score: 62.6 (Unranked · 2 rankable rows)
- Claude Sonnet 5.5 public-lane score: 83.3 (Unranked · 7 rankable rows)

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| Blueprint-Bench 2 | 38.6% | Coming soon | Coming soon |
| OfficeQA Pro | 57.9% | 65.6% | Claude Sonnet 5.5 |
| Chartography (no tools) | Coming soon | 61.6% | Coming soon |
| Chartography (tools) | Coming soon | 90.2% | Coming soon |
| BenchCAD Vision2Code (no tools) | Coming soon | 0.747 | Coming soon |
| BenchCAD Vision2Code (tools) | Coming soon | 0.963 | Coming soon |
| Biomedical image analysis | Coming soon | 72.2% | Coming soon |
| OfficeQA | Coming soon | 76.9% | Coming soon |

### Knowledge

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 81.7 (Supported · #4/160)
- Claude Sonnet 5.5 public-lane score: 80.9 (Supported · #6/160)

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 93.2% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 91.5% | Coming soon | Coming soon |
| HealthBench (raw) | Coming soon | 69.4% | Coming soon |
| HealthBench (length-adjusted) | Coming soon | 65.4% | Coming soon |
| HealthBench Professional (raw) | Coming soon | 77.1% | Coming soon |
| HealthBench Professional | Coming soon | 69.2% | Coming soon |
| BioMysteryBench (human-solvable) | Coming soon | 89.2% | Coming soon |
| BioMysteryBench (human-difficult) | Coming soon | 44.7% | Coming soon |
| SpatialBench Verified | Coming soon | 72.5% | Coming soon |
| SingleCellBench | Coming soon | 59.1% | Coming soon |
| Protein Design | Coming soon | 51.0% | Coming soon |
| Morphology-to-molecule matching | Coming soon | 25.0% | Coming soon |
| Medicinal chemistry | Coming soon | 65.3% | Coming soon |
| Protein Design library ranking | Coming soon | 54.8% | Coming soon |
| De novo protein-binder design | Coming soon | 82.3% | Coming soon |
| Protocols (troubleshooting) | Coming soon | 67.3% | Coming soon |
| Protocols (understanding) | Coming soon | 66.6% | Coming soon |
| HLE w/o tools | Coming soon | 56.9% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Fable 5 public-lane score: Coming soon
- Claude Sonnet 5.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | Coming soon | 92.1% | Coming soon |
| MILU | Coming soon | 91.6% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Fable 5 public-lane score: 75.7 (#58/124)
- Claude Sonnet 5.5 public-lane score: Coming soon

### Mathematics

- Winner: Not comparable
- Claude Fable 5 public-lane score: Coming soon
- Claude Sonnet 5.5 public-lane score: Coming soon

| Benchmark | Claude Fable 5 | Claude Sonnet 5.5 | Winner |
|-----------|-----------|-----------|--------|
| ArXivMath Aug. 2026 (no tools) | Coming soon | 86.8% | Coming soon |
| ArXivMath Aug. 2026 (tools) | Coming soon | 95.2% | Coming soon |

## FAQ

### Which is better overall, Claude Fable 5 or Claude Sonnet 5.5?

Claude Sonnet 5.5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Fable 5 and Claude Sonnet 5.5?

The widest category gap is in multimodal & grounded, where the averages are 62.6 for Claude Fable 5 and 83.3 for Claude Sonnet 5.5.

### How many benchmarks does Claude Fable 5 cover on BenchLM?

Claude Fable 5 currently has 21 sourced benchmark scores on BenchLM.

### How many benchmarks does Claude Sonnet 5.5 cover on BenchLM?

Claude Sonnet 5.5 currently has 47 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5 vs Claude Fable 5.1](/compare/claude-fable-vs-claude-fable-5-1)
- [Claude Sonnet 5.5 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-claude-sonnet-5-5)
- [Claude Fable 5 vs GPT-6 Astra](/compare/claude-fable-vs-gpt-6-astra)
- [Claude Sonnet 5.5 vs GPT-6 Astra](/compare/claude-sonnet-5-5-vs-gpt-6-astra)

## Explore More

- [Claude Fable 5 profile](/models/claude-fable)
- [Claude Sonnet 5.5 profile](/models/claude-sonnet-5-5)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)