# Claude Fable 5.1 vs Claude Opus 5

> Side-by-side benchmark comparison for Claude Fable 5.1 and Claude Opus 5 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

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

- Shared sourced benchmarks: 29
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick Claude Fable 5.1 if you want the stronger benchmark profile. Claude Opus 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 79.63.
- The clearest category separation is in coding, where the averages are 76.8 for Claude Fable 5.1 and 70.7 for Claude Opus 5.
- The biggest single benchmark swing is ApprenticeBench in Agentic, with scores of 72% and 36%.
- Claude Opus 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 | Claude Opus 5 |
|----------|----------|----------|
| Creator | Anthropic | Anthropic |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | null |
| Overall Score | 83.18 | 79.63 |
| Benchmarks Covered | 33 | 80 |
| Pricing (input/output) | $10.00 / $50.00 | $5.00 / $25.00 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)
- Claude Opus 5 public-lane score: 78.5 (Supported · #3/128)

| Benchmark | Claude Fable 5.1 | Claude Opus 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% | 70.6% | Claude Opus 5 |
| AutomationBench | 31.4% | 26.0% | Claude Fable 5.1 |
| Toolathlon-Verified | 77.8% | 80.6% | Claude Opus 5 |
| Toolathlon Verified Pass@3 | 81.5% | 87.0% | Claude Opus 5 |
| Toolathlon Verified Pass³ | 73.1% | 73.1% | Tie |
| Toolathlon Verified avg. turns | 23.7 turns | 23.5 turns | Claude Fable 5.1 |
| Terminal-Bench 2.1 (Vals) | 85.0% | 84.6% | Claude Fable 5.1 |
| ApprenticeBench | 72% | 36% | Claude Fable 5.1 |
| CWE-bench v1 | 58.0% | Coming soon | Coming soon |
| MazeBench | 10% | 12% | Claude Opus 5 |
| Terminal-Bench 3.0 | Coming soon | 42.7% | Coming soon |
| BrowseComp | Coming soon | 90.8% | Coming soon |
| HLE w/ tools | Coming soon | 64.7% | Coming soon |
| DeepSearchQA | Coming soon | 95.0% | Coming soon |
| DRACO | Coming soon | 88.6% | Coming soon |
| BrowseComp (10-agent, prerelease) | Coming soon | 93.6% | Coming soon |
| MCP Atlas | Coming soon | 85.8% | Coming soon |
| MCP-Atlas claim coverage | Coming soon | 89.1% | Coming soon |
| LAB all-pass (Anthropic harness) | Coming soon | 23.58% | Coming soon |
| LAB criterion-pass (Anthropic harness) | Coming soon | 93.74% | Coming soon |
| LAB all-pass (Harvey held-out) | Coming soon | 11.7% | Coming soon |
| LAB criterion-pass (Harvey held-out) | Coming soon | 94.1% | Coming soon |

### Coding

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)
- Claude Opus 5 public-lane score: 70.7 (Supported · #9/150)

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43.0 fixes | 27.0 fixes | Claude Fable 5.1 |
| SWE-bench Pro | 81.2% | 79.2% | Claude Fable 5.1 |
| SWE Multilingual | 89.1% | 89.5% | Claude Opus 5 |
| SWE Multimodal | 54.7% | 59.4% | Claude Opus 5 |
| DeepSWE | 67.4% | 68.8% | Claude Opus 5 |
| FrontierSWE v2 | 56.3% | 52.0% | Claude Fable 5.1 |
| ProgramBench | 87.6% | 93.0% | Claude Opus 5 |
| CursorBench 3.2 | 73.4% | 70.0% | Claude Fable 5.1 |
| LiveCodeBench (Vals) | 90.5% | 89.0% | Claude Fable 5.1 |
| CursorBench 4.0 | 51.8% | 46.6% | Claude Fable 5.1 |
| PostTrainBench v1.1 | 40.2% | 35.0% | Claude Fable 5.1 |
| SWE-bench Verified | Coming soon | 96% | Coming soon |
| FrontierCode 1.1 Main | Coming soon | 53.4% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 63.6% | Coming soon |
| ProgramBench (episode 1) | Coming soon | 83.0% | Coming soon |
| VulcanBench v3 | Coming soon | 87.0% | Coming soon |
| VulcanBench CII v1 | Coming soon | 96.4% | Coming soon |
| SWE-bench (Vals) | Coming soon | 97.0% | Coming soon |

### Reasoning

- Winner: Directional only
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)
- Claude Opus 5 public-lane score: 81 (#11/28)

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 97.50% | 97.50% | Tie |
| ARC-AGI-2 | 90% | 90.4% | Claude Opus 5 |
| GraphWalks BFS 256K–1M | 65.0% | Coming soon | Coming soon |
| ARC-AGI-3 | Coming soon | 30.2% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Claude Opus 5 public-lane score: 92.2 (#2/54)

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| Chartography (no tools) | Coming soon | 29.6% | Coming soon |
| Chartography (tools) | Coming soon | 83.0% | Coming soon |
| BenchCAD Vision2Code (no tools) | Coming soon | 0.366 | Coming soon |
| BenchCAD Vision2Code (tools) | Coming soon | 0.821 | Coming soon |
| GDP.pdf (no tools) | Coming soon | 83.4% | Coming soon |
| GDP.pdf (tools) | Coming soon | 85.5% | Coming soon |
| OfficeQA | Coming soon | 78.1% | Coming soon |
| OfficeQA Pro | Coming soon | 66.9% | Coming soon |

### Knowledge

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)
- Claude Opus 5 public-lane score: 82 (Supported · #7/184)

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| HLE | 65% | 64.7% | Claude Fable 5.1 |
| HLE w/o tools | 60.9% | 56.3% | Claude Fable 5.1 |
| GPQA Diamond (Vals) | 93.4% | 93.4% | Tie |
| MMLU-Pro (Vals) | 92.4% | 91.6% | Claude Fable 5.1 |
| HLE-Verified | Coming soon | 54.4% | Coming soon |
| LABBench2 | Coming soon | 84.2% | Coming soon |
| HealthBench (raw) | Coming soon | 67.1% | Coming soon |
| HealthBench (length-adjusted) | Coming soon | 57.8% | Coming soon |
| HealthBench Professional | Coming soon | 59.8% | Coming soon |
| HealthBench Professional (raw) | Coming soon | 73.4% | Coming soon |
| BioMysteryBench (human-solvable) | Coming soon | 90.1% | Coming soon |
| BioMysteryBench (human-difficult) | Coming soon | 49.4% | Coming soon |
| SpatialBench Verified | Coming soon | 72.5% | Coming soon |
| SingleCellBench | Coming soon | 60.6% | Coming soon |
| ProteinGym Hard | Coming soon | 47.7% | Coming soon |
| Protein Design | Coming soon | 42.5% | Coming soon |
| Organic chemistry V2 | Coming soon | 61.6% | Coming soon |
| Protocols (troubleshooting) | Coming soon | 61.1% | Coming soon |
| Protocols (understanding) | Coming soon | 78.4% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Claude Opus 5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| GMMLU | Coming soon | 92.5% | Coming soon |
| MILU | Coming soon | 92.1% | Coming soon |
| INCLUDE | Coming soon | 89.8% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Claude Opus 5 public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 1.0% | 4.6% | Claude Fable 5.1 |

### Mathematics

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)
- Claude Opus 5 public-lane score: 91.6 (Unranked · 7 rankable rows)

| Benchmark | Claude Fable 5.1 | Claude Opus 5 | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 90.175% | 85.614% | Claude Fable 5.1 |
| FrontierMath v2 (Tier 4) | 87.805% | 73.171% | Claude Fable 5.1 |
| IMO 2026 | Coming soon | 42/42 | Coming soon |
| RiemannBench (no tools) | Coming soon | 60.0% | Coming soon |
| RiemannBench (tools) | Coming soon | 79.0% | Coming soon |
| ArXivMath Jun. 2026 (no tools) | Coming soon | 90.8% | Coming soon |
| ArXivMath Jun. 2026 (tools) | Coming soon | 91.3% | Coming soon |

## FAQ

### Which is better overall, Claude Fable 5.1 or Claude Opus 5?

Claude Fable 5.1 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Fable 5.1 and Claude Opus 5?

The widest category gap is in coding, where the averages are 76.8 for Claude Fable 5.1 and 70.7 for Claude Opus 5.

### 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 Claude Opus 5 cover on BenchLM?

Claude Opus 5 currently has 80 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [Claude Opus 5 vs Claude Fable 5](/compare/claude-fable-vs-claude-opus-5)
- [Claude Fable 5.1 vs Claude Opus 5.5](/compare/claude-fable-5-1-vs-claude-opus-5-5)
- [Claude Opus 5 vs Claude Opus 5.5](/compare/claude-opus-5-vs-claude-opus-5-5)

## Explore More

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