# Claude Fable 5.1 vs Inkling

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

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

- Shared sourced benchmarks: 11
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick Claude Fable 5.1 if you want the stronger benchmark profile. Inkling 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 52.6.
- The clearest category separation is in agentic, where the averages are 80.9 for Claude Fable 5.1 and 37.2 for Inkling.
- The biggest single benchmark swing is FrontierMath v2 (Tier 4) in Mathematics, with scores of 87.805% and 4.878%.
- Inkling is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Fable 5.1 | Inkling |
|----------|----------|----------|
| Creator | Anthropic | Thinking Machines Lab |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Hybrid |
| Context | 1M | 1M |
| Overall Score | 83.18 | 52.6 |
| Benchmarks Covered | 33 | 24 |
| Pricing (input/output) | $10.00 / $50.00 | $1.87 / $4.68 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)
- Inkling public-lane score: 37.2 (Supported · #74/128)

| Benchmark | Claude Fable 5.1 | Inkling | 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% | 47.6% | Claude Fable 5.1 |
| ApprenticeBench | 72% | Coming soon | Coming soon |
| CWE-bench v1 | 58.0% | 37.0% | Claude Fable 5.1 |
| MazeBench | 10% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 63.8% | Coming soon |
| BrowseComp | Coming soon | 77.1% | Coming soon |
| MCP Atlas | Coming soon | 74.1% | Coming soon |

### Coding

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)
- Inkling public-lane score: 33.9 (Supported · #82/150)

| Benchmark | Claude Fable 5.1 | Inkling | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43.0 fixes | Coming soon | Coming soon |
| SWE-bench Pro | 81.2% | 54.3% | Claude Fable 5.1 |
| 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% | 4.1% | Claude Fable 5.1 |
| ProgramBench | 87.6% | Coming soon | Coming soon |
| CursorBench 3.2 | 73.4% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 90.5% | 85.5% | Claude Fable 5.1 |
| CursorBench 4.0 | 51.8% | Coming soon | Coming soon |
| PostTrainBench v1.1 | 40.2% | Coming soon | Coming soon |
| SWE-bench Verified | Coming soon | 77.6% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 63.8% | Coming soon |
| SWE-bench (Vals) | Coming soon | 77.6% | Coming soon |

### Reasoning

- Winner: Directional only
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)
- Inkling public-lane score: 79 (#14/28)

| Benchmark | Claude Fable 5.1 | Inkling | 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 |

### Multimodal & Grounded

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Inkling public-lane score: 67.5 (#35/54)

| Benchmark | Claude Fable 5.1 | Inkling | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | Coming soon | 73.5% | Coming soon |
| CharXiv | Coming soon | 82% | Coming soon |
| CharXiv w/o tools | Coming soon | 78.1% | Coming soon |

### Knowledge

- Winner: Claude Fable 5.1
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)
- Inkling public-lane score: 54.6 (Supported · #63/184)

| Benchmark | Claude Fable 5.1 | Inkling | Winner |
|-----------|-----------|-----------|--------|
| HLE | 65% | 46% | Claude Fable 5.1 |
| HLE w/o tools | 60.9% | 30% | Claude Fable 5.1 |
| GPQA Diamond (Vals) | 93.4% | 87.1% | Claude Fable 5.1 |
| MMLU-Pro (Vals) | 92.4% | 86.3% | Claude Fable 5.1 |
| GPQA | Coming soon | 87.9% | Coming soon |
| GPQA-D | Coming soon | 87.9% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: Coming soon
- Inkling public-lane score: 87.6 (#36/148)

| Benchmark | Claude Fable 5.1 | Inkling | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 1.0% | Coming soon | Coming soon |
| IFBench | Coming soon | 79.8% | Coming soon |

### Mathematics

- Winner: Not comparable
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)
- Inkling public-lane score: 58.3 (#11/12)

| Benchmark | Claude Fable 5.1 | Inkling | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 90.175% | 33.333% | Claude Fable 5.1 |
| FrontierMath v2 (Tier 4) | 87.805% | 4.878% | Claude Fable 5.1 |
| AIME26 | Coming soon | 97.1% | Coming soon |

## FAQ

### Which is better overall, Claude Fable 5.1 or Inkling?

Claude Fable 5.1 is ahead overall on BenchLM right now.

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

The widest category gap is in agentic, where the averages are 80.9 for Claude Fable 5.1 and 37.2 for Inkling.

### 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 Inkling cover on BenchLM?

Inkling currently has 24 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [Inkling vs Claude Fable 5](/compare/claude-fable-vs-inkling)
- [Claude Fable 5.1 vs Inkling-Small](/compare/claude-fable-5-1-vs-inkling-small)
- [Inkling vs Inkling-Small](/compare/inkling-vs-inkling-small)

## Explore More

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