# Claude Fable 5.1 vs DeepSeek V3.1 (Reasoning)

> Side-by-side benchmark comparison for Claude Fable 5.1 and DeepSeek V3.1 (Reasoning) across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-5-1-vs-deepseek-v3-1-reasoning
- Last updated: October 17, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Claude Fable 5.1 and DeepSeek V3.1 (Reasoning) share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- DeepSeek V3.1 (Reasoning) has the lower published output-token price.
- Claude Fable 5.1 has the larger published context window at 1M.

## Model Snapshot

| Property | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) |
|----------|----------|----------|
| Creator | Anthropic | DeepSeek |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 128K |
| Independent public score (not head-to-head) | 83.18 | 39.18 |
| Benchmarks Covered | 33 | 6 |
| Pricing (input/output) | $10.00 / $50.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 80.9 (Supported · #2/128)
- DeepSeek V3.1 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | 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% | Coming soon | Coming soon |
| ApprenticeBench | 72% | Coming soon | Coming soon |
| CWE-bench v1 | 58.0% | Coming soon | Coming soon |
| MazeBench | 10% | Coming soon | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 76.8 (Supported · #3/150)
- DeepSeek V3.1 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| Bug Hunt Bench | 43.0 fixes | Coming soon | Coming soon |
| 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% | Coming soon | Coming soon |
| FrontierSWE v2 | 56.3% | Coming soon | Coming soon |
| 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% | Coming soon | Coming soon |
| LiveCodeBench | Coming soon | 74.8% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 85.2 (#4/28)
- DeepSeek V3.1 (Reasoning) public-lane score: 64.8 (Unranked · 2 rankable rows)

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | 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: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 86.9 (Supported · #2/184)
- DeepSeek V3.1 (Reasoning) public-lane score: 40.7 (Supported · #116/184)

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| HLE | 65% | 15.9% | Claude Fable 5.1 |
| 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 | 80.1% | Coming soon |
| MMLU-Pro | Coming soon | 84.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: Coming soon
- DeepSeek V3.1 (Reasoning) public-lane score: 48.4 (#95/148)

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| Gray Swan IPI (15 attempts) | 1.0% | Coming soon | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- Claude Fable 5.1 public-lane score: 96.8 (Unranked · 2 rankable rows)
- DeepSeek V3.1 (Reasoning) public-lane score: Coming soon

| Benchmark | Claude Fable 5.1 | DeepSeek V3.1 (Reasoning) | Winner |
|-----------|-----------|-----------|--------|
| FrontierMath v2 (Tiers 1-3) | 90.175% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 87.805% | Coming soon | Coming soon |
| AIME 2024 | Coming soon | 93.1% | Coming soon |
| AIME 2025 | Coming soon | 88.4% | Coming soon |

## FAQ

### Is there enough evidence to pick between Claude Fable 5.1 and DeepSeek V3.1 (Reasoning)?

Not yet. The models share only 1 sourced benchmark row, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Claude Fable 5.1 vs Claude Fable 5](/compare/claude-fable-vs-claude-fable-5-1)
- [DeepSeek V3.1 (Reasoning) vs Claude Fable 5](/compare/claude-fable-vs-deepseek-v3-1-reasoning)
- [Claude Fable 5.1 vs DeepSeek V3.1](/compare/claude-fable-5-1-vs-deepseek-v3-1)
- [DeepSeek V3.1 (Reasoning) vs DeepSeek V3.1](/compare/deepseek-v3-1-vs-deepseek-v3-1-reasoning)

## Explore More

- [Claude Fable 5.1 profile](/models/claude-fable-5-1)
- [DeepSeek V3.1 (Reasoning) profile](/models/deepseek-v3-1-reasoning)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)