# Aion 3.5 vs Claude Fable 5

> Claude Fable 5 has enough public results to be ranked (#5); Aion 3.5 does not yet, so treat this comparison as directional.

- Canonical page: https://noometry.com/compare/aion-3-5-vs-claude-fable-5
- Last updated: 2026-10-10
- Shared benchmarks: 1

## Summary

- They share 1 benchmark with published results for both. Aion 3.5 scores higher in 0 categories and Claude Fable 5 in 1 category; one gap is clear of the uncertainty.
- Aion 3.5 is cheaper at $3 / $6 per million input/output tokens, against $10 / $50 for Claude Fable 5.
- Claude Fable 5 accepts more context: 1M tokens versus 262K.

## Snapshot

| | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| Provider | AionLabs | Anthropic |
| Noometry Index | 57.9 | 66.3 |
| Rank | — | 5 |
| Context | 262K | 1M |
| Input $/M | $3 | $10 |
| Output $/M | $6 | $50 |
| Weights | Proprietary | Proprietary |

## Coding

- Aion 3.5: —
- Claude Fable 5: 67.0 (#4)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| DeepSWE | — | 69.9% |
| FrontierCode | — | 53.5% |
| LMArena WebDev | — | 1626 |
| FrontierSWE | — | 47% |
| SciCode | — | 61% |
| WeirdML | — | 91.9% |
| LMArena Coding | — | 1519 |
| MirrorCode | — | 63.9% |
| ALE-Bench | — | 2,041 |

## Agentic & Tool Use

- Aion 3.5: —
- Claude Fable 5: 54.1 (#2)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| APEX-Agents | — | 63.6% |
| Remote Labor Index | — | 16.1% |
| τ²-bench Banking | — | 39.7% |
| PostTrainBench | — | 41.8% |
| GBAEval | — | 74.5% |
| GDP.pdf | — | 30% |
| LMArena Search | — | 1230 |
| Vending-Bench 2 | — | 5,680 |

## Reasoning

- Aion 3.5: —
- Claude Fable 5: 76.8 (#4)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| ARC-AGI-2 | — | 89.2% |
| SimpleBench | — | 81.9% |
| Kagi LLM Benchmark | — | 91.4% |
| NYT Connections (extended) | — | 92.7% |
| ARC-AGI-1 | — | 98.5% |
| CritPt | — | 28.6% |
| Chess Puzzles | — | 41% |
| EnigmaEval | — | 39.3% |
| EBR-Bench | — | 39.5% |
| LMArena Hard Prompts | — | 1508 |
| Mystery Game Puzzles | — | 52% |
| DTBench | — | 98.4% |
| LMCA | — | 61.1% |
| Surface Evolver Bench | — | 95% |
| Bench to the Future 3 | — | 0.13 |
| Epoch Capabilities Index | — | 163.6 |

## Math

- Aion 3.5: —
- Claude Fable 5: 88.4 (#5)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 87% |
| FrontierMath Tier 4 | — | 90.2% |
| OTIS Mock AIME 2024-2025 | — | 100% |
| ProofBench | — | 95% |
| LMArena Math | — | 1519 |
| FrontierMath Erdős | — | 0% |

## Knowledge

- Aion 3.5: —
- Claude Fable 5: 62.3 (#22)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| GPQA Diamond | — | 85.9% |
| SimpleQA Verified | — | 70.7% |
| LMArena Expert | — | 1534 |

## Multimodal

- Aion 3.5: —
- Claude Fable 5: 45.6 (#14)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| LMArena Vision | — | 1326 |
| Blueprint-Bench 2 | — | 38.6% |
| Furniture Assembly | — | 35.8% |
| LMArena Document | — | 1496 |

## Multilingual

- Aion 3.5: —
- Claude Fable 5: 57.6 (#8)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| LMArena Non-English | — | 1483 |
| LMArena Chinese | — | 1546 |
| LMArena French | — | 1509 |
| LMArena German | — | 1486 |
| LMArena Japanese | — | 1507 |
| LMArena Korean | — | 1493 |
| LMArena Russian | — | 1507 |
| LMArena Spanish | — | 1503 |

## Instruction Following

- Aion 3.5: —
- Claude Fable 5: 78.8 (#7)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| LMArena Instruction Following | — | 1503 |

## Long Context

- Aion 3.5: —
- Claude Fable 5: 46.3 (#22)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| LMArena Longer Query | — | 1510 |

## Writing & Preference

- Aion 3.5: 74.9
- Claude Fable 5: 76.1 (#5)

| Benchmark | Aion 3.5 | Claude Fable 5 |
|---|---|---|
| EQ-Bench Creative Writing | 1929 | 1943 |
| LMArena Text | — | 1491 |
| LMArena Creative Writing | — | 1494 |
| EQ-Bench 4 | — | 1340 |
| LMArena Multi-Turn | — | 1505 |

## FAQ

### Is Aion 3.5 better than Claude Fable 5?

Claude Fable 5 has enough public results to be ranked (#5); Aion 3.5 does not yet, so treat this comparison as directional.

### Which is cheaper, Aion 3.5 or Claude Fable 5?

Aion 3.5 is cheaper. It lists at $3 per million input tokens and $6 per million output tokens; Claude Fable 5 lists at $10 and $50.

### Which has the bigger context window?

Claude Fable 5 does, with 1M tokens against 262K.

### How many benchmarks do Aion 3.5 and Claude Fable 5 share?

1 benchmark has published results for both models. Aion 3.5 has 1 scored results on Noometry and Claude Fable 5 has 61.