# Claude Fable 5.1 vs GPT-6 Astra

> Side-by-side benchmark comparison for Claude Fable 5.1 and GPT-6 Astra across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-5-1-vs-gpt-6-astra
- Last updated: October 17, 2026

- Shared sourced benchmarks: 18
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick GPT-6 Astra if you want the stronger benchmark profile. Claude Fable 5.1 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- GPT-6 Astra leads overall 83.88 to 83.18.
- The clearest category separation is in reasoning, where the averages are 85.2 for Claude Fable 5.1 and 93.3 for GPT-6 Astra.
- The biggest single benchmark swing is OSWorld 2.0 in Agentic, with scores of 41.7% and 72.6%.
- GPT-6 Astra also has the larger context window at 1.05M.

## Model Snapshot

| Property | Claude Fable 5.1 | GPT-6 Astra |
|----------|----------|----------|
| Creator | Anthropic | OpenAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 1.05M |
| Overall Score | 83.18 | 83.88 |
| Benchmarks Covered | 33 | 40 |
| Pricing (input/output) | $10.00 / $50.00 | $10.00 / $50.00 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)
- GPT-6 Astra public-lane score: 74.8 (Supported · #7/128)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 4.0 | 55.80% | 57.90% | GPT-6 Astra |
| Terminal-Bench-Science 0.1 | 52.6% | 64.6% | GPT-6 Astra |
| OSWorld 2.0 | 41.7% | 72.6% | GPT-6 Astra |
| AutomationBench | 31.4% | 41.4% | GPT-6 Astra |
| 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% | 87.3% | GPT-6 Astra |
| ApprenticeBench | 72% | 68% | Claude Fable 5.1 |
| CWE-bench v1 | 58.0% | 68.0% | GPT-6 Astra |
| MazeBench | 10% | 23% | GPT-6 Astra |
| BrowseComp | Coming soon | 91.5% | Coming soon |
| ExploitGym | Coming soon | 42.4% | Coming soon |
| Agents' Last Exam | Coming soon | 59.3% | Coming soon |
| HLE w/ tools | Coming soon | 57.2% | Coming soon |
| Hermes Index | Coming soon | 56.3% | Coming soon |
| Hermes Bench | Coming soon | 73.7% | Coming soon |

### Coding

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)
- GPT-6 Astra public-lane score: 75.5 (Supported · #4/150)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43.0 fixes | 45.0 fixes | GPT-6 Astra |
| 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% | 74.1% | GPT-6 Astra |
| FrontierSWE v2 | 56.3% | 65.5% | GPT-6 Astra |
| ProgramBench | 87.6% | Coming soon | Coming soon |
| CursorBench 3.2 | 73.4% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 90.5% | Coming soon | Coming soon |
| CursorBench 4.0 | 51.8% | Coming soon | Coming soon |
| PostTrainBench v1.1 | 40.2% | 44.3% | GPT-6 Astra |
| FrontierCode 1.1 Main | Coming soon | 53.3% | Coming soon |
| FrontierCode 1.1 Extended | Coming soon | 64.5% | Coming soon |

### Reasoning

- Winner: Directional only
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)
- GPT-6 Astra public-lane score: 93.3 (#1/28)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-1 | 97.50% | 98.50% | GPT-6 Astra |
| ARC-AGI-2 | 90% | 95% | GPT-6 Astra |
| GraphWalks BFS 256K–1M | 65.0% | 71.8% | GPT-6 Astra |
| STEMBench | Coming soon | 2.81 | Coming soon |
| ARC-AGI-3 | Coming soon | 62.7% | Coming soon |
| GeneBench-Pro | Coming soon | 37.8% | Coming soon |
| MRCR v2 256K-512K | Coming soon | 100.0% | Coming soon |
| MRCR v2 512K-1M | Coming soon | 96.3% | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- GPT-6 Astra public-lane score: 87.3 (Unranked · 3 rankable rows)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| ScreenSpot Pro | Coming soon | 92.7% | Coming soon |
| BenchCAD Vision2Code (tools) | Coming soon | 0.959 | Coming soon |

### Knowledge

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)
- GPT-6 Astra public-lane score: 86.2 (Supported · #3/184)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | 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 |
| GPQA | Coming soon | 96% | Coming soon |
| GPQA-D | Coming soon | 96.0% | Coming soon |
| HealthBench (raw) | Coming soon | 56.9% | Coming soon |
| HealthBench (length-adjusted) | Coming soon | 58.3% | Coming soon |
| HealthBench Professional | Coming soon | 64.7% | Coming soon |
| HealthBench Professional (raw) | Coming soon | 68.2% | Coming soon |
| HealthBench Hard | Coming soon | 36.6% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- GPT-6 Astra public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 1.0% | 8.5% | Claude Fable 5.1 |

### Mathematics

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)
- GPT-6 Astra public-lane score: 97.3 (Unranked · 2 rankable rows)

| Benchmark | Claude Fable 5.1 | GPT-6 Astra | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 90.175% | 93.684% | GPT-6 Astra |
| FrontierMath v2 (Tier 4) | 87.805% | 97.600% | GPT-6 Astra |

## FAQ

### Which is better overall, Claude Fable 5.1 or GPT-6 Astra?

GPT-6 Astra is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Fable 5.1 and GPT-6 Astra?

The widest category gap is in reasoning, where the averages are 85.2 for Claude Fable 5.1 and 93.3 for GPT-6 Astra.

### 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 GPT-6 Astra cover on BenchLM?

GPT-6 Astra currently has 40 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [GPT-6 Astra vs Claude Fable 5](/compare/claude-fable-vs-gpt-6-astra)
- [Claude Fable 5.1 vs GPT-6.1 Sol](/compare/claude-fable-5-1-vs-gpt-6-1-sol)
- [GPT-6 Astra vs GPT-6.1 Sol](/compare/gpt-6-1-sol-vs-gpt-6-astra)

## Explore More

- [Claude Fable 5.1 profile](/models/claude-fable-5-1)
- [GPT-6 Astra profile](/models/gpt-6-astra)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)