Aion 3.5 vs Claude Fable 5
Aion 3.5 costs 8.3x less per output token than Claude Fable 5 ($6.00 vs $50.00 per million). Updated October 22, 2026; no benchmark has tested both models yet.
A Aion 3.5Aion Labs
- Coding
- No data
- Overall
- No data
- Output $/M
- $6.00
Claude Fable 5Anthropic
- Coding
- 79.3
- Overall
- 79.0
- Output $/M
- $50.00
vs $6.00 vs $50.00 per 1M output tokens. Aion 3.5 is 8.3x cheaper.
Aion 3.5 or Claude Fable 5: which to pick
Only Claude Fable 5 has a coding score, 79.3 on the Vibe Coding Index; Aion 3.5 has none, so the two cannot be ranked on coding.
Pick Aion 3.5 for output tokens 8.3x cheaper ($6.00 vs $50.00 per million).
Model AAion 3.5Aion LabsNot benchmarkedNo coding benchmarkNo cost per solved taskModel BClaude Fable 5Anthropic79.3/1006 independent benchmarks$2.16 per solved task
No benchmark has tested both yet. Aion 3.5 has none yet; Claude Fable 5 on LiveBench coding, LMArena WebDev and AA Coding Index. Compare them on price and context instead.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Only Claude Fable 5 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Claude Fable 5 has a AA Intelligence Index result, 49.6.
Directional only
Agentic work
AA Agentic Index
No call
Only Claude Fable 5 has a AA Agentic Index result, 50.7.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Fable 5 has a GPQA Diamond result, 93.2%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Fable 5 has a MMLU Pro result, 91.5%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Fable 5 has a Design Arena: websites result, 1295.
Directional only
Long documents
Listed context window
Claude Fable 5
Claude Fable 5 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Aion 3.5
Aion 3.5 $0.0060, Claude Fable 5 $0.035 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Fable 5 has the number, $2.16.
Directional only
At a glance
- Coding index
- Aion 3.5 not benchmarked, Claude Fable 5 79.3 from 6 benchmarks.
- Widest category
- None yet: no category has been tested on both models.
- Widest single gap
- None yet: no benchmark has tested both models.
- Output price
- Aion 3.5 $6.00 against Claude Fable 5 $50.00 per million output tokens, 8.3x apart.
- Context window
- Aion 3.5 takes 262K tokens, Claude Fable 5 1M.
Benchmark by benchmark
Every board either model has a result on, a category to a fold; bars are each result on a 0 to 100 scale. Only one model is measured on each, so no row names a leader.
CodingDirectional onlySix of these boards feed the Vibe Coding Index26 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 98.3% | Only Claude Fable 5 measured |
| LMArena WebDev | Not measured | 1624 | Only Claude Fable 5 measured |
| AA Coding Index | Not measured | 76.5 | Only Claude Fable 5 measured |
| LiveCodeBench (Vals AI) | Not measured | 89.8% | Only Claude Fable 5 measured |
| SWE-bench Verified (Vals AI) | Not measured | 95.0% | Only Claude Fable 5 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 41.4% | Only Claude Fable 5 measured |
| Vibe Code Bench (Vals AI) | Not measured | 90.3% | Only Claude Fable 5 measured |
| Code migration (Vals AI) | Not measured | 55.1% | Only Claude Fable 5 measured |
| ProgramBench (Vals AI) | Not measured | 2.0% | Only Claude Fable 5 measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 80.5% | Only Claude Fable 5 measured |
| SciCode | Not measured | 61.0% | Only Claude Fable 5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 62.9% | Only Claude Fable 5 measured |
| FrontierCode | Not measured | 53.5% | Only Claude Fable 5 measured |
| FrontierSWE | Not measured | 47.0% | Only Claude Fable 5 measured |
| GSO-Bench | Not measured | 78.4% | Only Claude Fable 5 measured |
| WeirdML | Not measured | 91.9% | Only Claude Fable 5 measured |
| MirrorCode | Not measured | 63.9% | Only Claude Fable 5 measured |
| ALE-Bench | Not measured | 2041.3 | Only Claude Fable 5 measured |
| LMArena Text: coding | Not measured | 1518 | Only Claude Fable 5 measured |
| LMArena Text: software and IT | Not measured | 1513 | Only Claude Fable 5 measured |
| LMArena WebDev: React | Not measured | 1631 | Only Claude Fable 5 measured |
| LMArena WebDev: HTML | Not measured | 1651 | Only Claude Fable 5 measured |
| LMArena WebDev: from an image | Not measured | 1623 | Only Claude Fable 5 measured |
| SWE Atlas: Codebase QnA | Not measured | 39.0% | Only Claude Fable 5 measured |
| SWE Atlas: Refactoring | Not measured | 54.8% | Only Claude Fable 5 measured |
| SWE Atlas: Test Writing | Not measured | 55.6% | Only Claude Fable 5 measured |
| Neither model has a result on the other 17 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 49.6 | Only Claude Fable 5 measured |
| Epoch Capabilities Index | Not measured | 163.4 | Only Claude Fable 5 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index24 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 50.7 | Only Claude Fable 5 measured |
| Design Arena: agents building web apps | Not measured | 1261 | Only Claude Fable 5 measured |
| Design Arena: agents building full-stack apps | Not measured | 1280 | Only Claude Fable 5 measured |
| Design Arena: agents building mobile apps | Not measured | 1263 | Only Claude Fable 5 measured |
| Design Arena: agents building Android apps | Not measured | 1283 | Only Claude Fable 5 measured |
| Design Arena: agents building Godot games | Not measured | 1292 | Only Claude Fable 5 measured |
| Design Arena: agents building games | Not measured | 1285 | Only Claude Fable 5 measured |
| Design Arena: HTML slides | Not measured | 1216 | Only Claude Fable 5 measured |
| Design Arena: PowerPoint slides | Not measured | 1269 | Only Claude Fable 5 measured |
| LiveBench research | Not measured | 86.9% | Only Claude Fable 5 measured |
| LiveBench browser | Not measured | 92.0% | Only Claude Fable 5 measured |
| LiveBench long agentic | Not measured | 53.2% | Only Claude Fable 5 measured |
| Finance Agent (Vals AI) | Not measured | 56.3% | Only Claude Fable 5 measured |
| Tax Agent Bench (Vals AI) | Not measured | 38.3% | Only Claude Fable 5 measured |
| Legal Research Bench (Vals AI) | Not measured | 49.5% | Only Claude Fable 5 measured |
| Excel Modeling Benchmark (Vals AI) | Not measured | 73.7% | Only Claude Fable 5 measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 15.7% | Only Claude Fable 5 measured |
| τ²-Bench Telecom | Not measured | 98.5% | Only Claude Fable 5 measured |
| APEX-Agents | Not measured | 63.6% | Only Claude Fable 5 measured |
| Remote Labor Index | Not measured | 16.1% | Only Claude Fable 5 measured |
| PostTrainBench | Not measured | 41.8% | Only Claude Fable 5 measured |
| Vending-Bench 2 | Not measured | $5,680 | Only Claude Fable 5 measured |
| LMArena Search | Not measured | 1229 | Only Claude Fable 5 measured |
| MCP Atlas | Not measured | 83.3% | Only Claude Fable 5 measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index18 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 93.2% | Only Claude Fable 5 measured |
| LiveBench reasoning | Not measured | 89.7% | Only Claude Fable 5 measured |
| MMMU Pro (Vals AI) | Not measured | 89.3% | Only Claude Fable 5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 92.6% | Only Claude Fable 5 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 55.5% | Only Claude Fable 5 measured |
| GPQA Diamond (Epoch AI run) | Not measured | 85.9% | Only Claude Fable 5 measured |
| ARC-AGI | Not measured | 98.5% | Only Claude Fable 5 measured |
| ARC-AGI-2 | Not measured | 89.2% | Only Claude Fable 5 measured |
| SimpleBench | Not measured | 81.9% | Only Claude Fable 5 measured |
| Chess puzzles | Not measured | 47.0% | Only Claude Fable 5 measured |
| Mystery game puzzles | Not measured | 52.0% | Only Claude Fable 5 measured |
| EBR-bench | Not measured | 39.5% | Only Claude Fable 5 measured |
| LMArena Text: hard prompts | Not measured | 1507 | Only Claude Fable 5 measured |
| LMArena Text: expert | Not measured | 1534 | Only Claude Fable 5 measured |
| LMArena Text: hard prompts in English | Not measured | 1509 | Only Claude Fable 5 measured |
| LMArena Vision: diagrams | Not measured | 1357 | Only Claude Fable 5 measured |
| LMArena Vision: homework | Not measured | 1361 | Only Claude Fable 5 measured |
| Kagi LLM Benchmark | Not measured | 91.4% | Only Claude Fable 5 measured |
| Neither model has a result on the other 5 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| OTIS Mock AIME | Not measured | 100.0% | Only Claude Fable 5 measured |
| FrontierMath, tiers 1 to 3 | Not measured | 87.0% | Only Claude Fable 5 measured |
| FrontierMath, tier 4 | Not measured | 90.2% | Only Claude Fable 5 measured |
| ProofBench | Not measured | 95.0% | Only Claude Fable 5 measured |
| LMArena Text: math | Not measured | 1516 | Only Claude Fable 5 measured |
| LMArena Text: mathematical work | Not measured | 1515 | Only Claude Fable 5 measured |
| MathArena | Not measured | 51.5% | Only Claude Fable 5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index13 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 91.5% | Only Claude Fable 5 measured |
| LegalBench (Vals AI) | Not measured | 88.6% | Only Claude Fable 5 measured |
| CorpFin (Vals AI) | Not measured | 71.8% | Only Claude Fable 5 measured |
| TaxEval (Vals AI) | Not measured | 76.9% | Only Claude Fable 5 measured |
| MortgageTax (Vals AI) | Not measured | 68.9% | Only Claude Fable 5 measured |
| MedCode (Vals AI) | Not measured | 56.1% | Only Claude Fable 5 measured |
| SimpleQA Verified | Not measured | 70.7% | Only Claude Fable 5 measured |
| LMArena Text: science | Not measured | 1506 | Only Claude Fable 5 measured |
| LMArena Text: medicine and healthcare | Not measured | 1480 | Only Claude Fable 5 measured |
| LMArena Text: legal and government | Not measured | 1498 | Only Claude Fable 5 measured |
| LMArena Text: business and finance | Not measured | 1480 | Only Claude Fable 5 measured |
| PRBench Finance | Not measured | 53.9% | Only Claude Fable 5 measured |
| PRBench Legal | Not measured | 52.6% | Only Claude Fable 5 measured |
| Neither model has a result on the other 7 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1295 | Only Claude Fable 5 measured |
| Design Arena: UI components | Not measured | 1316 | Only Claude Fable 5 measured |
| Design Arena: game dev | Not measured | 1335 | Only Claude Fable 5 measured |
| Design Arena: data viz | Not measured | 1305 | Only Claude Fable 5 measured |
| Design Arena: 3D | Not measured | 1318 | Only Claude Fable 5 measured |
| Design Arena: all code categories | Not measured | 1310 | Only Claude Fable 5 measured |
| Design Arena: SVG | Not measured | 1301 | Only Claude Fable 5 measured |
| Design Arena: ASCII art | Not measured | 1329 | Only Claude Fable 5 measured |
| LiveBench design | Not measured | 84.7% | Only Claude Fable 5 measured |
GeneralDirectional onlyPublic boards, shown as published, kept out of the index36 boards measured
| Benchmark | Aion 3.5 | Claude Fable 5 | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 80.5% | Only Claude Fable 5 measured |
| Public Benefits Bench (Vals AI) | Not measured | 70.4% | Only Claude Fable 5 measured |
| SAGE (Vals AI) | Not measured | 51.9% | Only Claude Fable 5 measured |
| MedScribe (Vals AI) | Not measured | 88.5% | Only Claude Fable 5 measured |
| Vals Multimodal Index | Not measured | 74.2% | Only Claude Fable 5 measured |
| IFBench | Not measured | 63.5% | Only Claude Fable 5 measured |
| Long context reasoning (AA-LCR) | Not measured | 82.3% | Only Claude Fable 5 measured |
| DTBench | Not measured | 98.4% | Only Claude Fable 5 measured |
| LMCA | Not measured | 61.2% | Only Claude Fable 5 measured |
| Surface Evolver Bench | Not measured | 95.0% | Only Claude Fable 5 measured |
| Furniture assembly | Not measured | 35.8% | Only Claude Fable 5 measured |
| LMArena Text | Not measured | 1491 | Only Claude Fable 5 measured |
| LMArena Text: instruction following | Not measured | 1502 | Only Claude Fable 5 measured |
| LMArena Text: creative writing | Not measured | 1494 | Only Claude Fable 5 measured |
| LMArena Vision | Not measured | 1325 | Only Claude Fable 5 measured |
| LMArena Text: English | Not measured | 1498 | Only Claude Fable 5 measured |
| LMArena Text: non-English | Not measured | 1482 | Only Claude Fable 5 measured |
| LMArena Text: Chinese | Not measured | 1543 | Only Claude Fable 5 measured |
| LMArena Text: German | Not measured | 1486 | Only Claude Fable 5 measured |
| LMArena Text: Japanese | Not measured | 1504 | Only Claude Fable 5 measured |
| LMArena Text: Korean | Not measured | 1487 | Only Claude Fable 5 measured |
| LMArena Text: French | Not measured | 1505 | Only Claude Fable 5 measured |
| LMArena Text: Spanish | Not measured | 1498 | Only Claude Fable 5 measured |
| LMArena Text: Russian | Not measured | 1503 | Only Claude Fable 5 measured |
| LMArena Text: Polish | Not measured | 1494 | Only Claude Fable 5 measured |
| LMArena Text: multi-turn | Not measured | 1504 | Only Claude Fable 5 measured |
| LMArena Text: longer queries | Not measured | 1510 | Only Claude Fable 5 measured |
| LMArena Text: writing and language | Not measured | 1501 | Only Claude Fable 5 measured |
| LMArena Text: entertainment and media | Not measured | 1482 | Only Claude Fable 5 measured |
| LMArena Vision: English | Not measured | 1323 | Only Claude Fable 5 measured |
| LMArena Vision: Chinese | Not measured | 1373 | Only Claude Fable 5 measured |
| LMArena Vision: reading text | Not measured | 1337 | Only Claude Fable 5 measured |
| LMArena Vision: humor | Not measured | 1341 | Only Claude Fable 5 measured |
| LMArena Vision: creative writing | Not measured | 1338 | Only Claude Fable 5 measured |
| LMArena Document | Not measured | 1496 | Only Claude Fable 5 measured |
| EQ-Bench 4 | Not measured | 1340 | Only Claude Fable 5 measured |
| Neither model has a result on the other 12 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Aion 3.5$0.0060Fits in one request
Claude Fable 5$0.035Fits in one request
Aion 3.5 costs less
Repository review
50K input + 3K output tokens
Aion 3.5$0.168Fits in one request
Claude Fable 5$0.650Fits in one request
Aion 3.5 costs less
Agent loop
200K input + 10K output tokens
Aion 3.5$0.660Fits in one request
Claude Fable 5$2.50Fits in one request
Aion 3.5 costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | AionLabs Aion 3.5 | Anthropic Claude Fable 5 |
|---|---|---|
| Maker | Aion Labs | Anthropic |
| Weights | No public weights listed | No public weights listed |
| Released | September 23, 2026 | June 9, 2026 |
| Context window | 262K | 1M |
| Input $/Mtok | $3.00 | $10.00 |
| Output $/Mtok | $6.00 | $50.00 |
| Coding index | Not benchmarked | 79.3 |
| Independent measurements behind it | 0 | 6 |
| Cost per solved task | Not computable | $2.16 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Aion 3.5 better than Claude Fable 5 for coding?
Only Claude Fable 5 has a coding score, 79.3 on the Vibe Coding Index; Aion 3.5 has none, so the two cannot be ranked on coding. Pick Aion 3.5 for output tokens 8.3x cheaper ($6.00 vs $50.00 per million).
Which is cheaper, Aion 3.5 or Claude Fable 5?
Aion 3.5 costs $3.00 per million input tokens and $6.00 per million output tokens; Claude Fable 5 costs $10.00 and $50.00. Cost per solved task is known for Claude Fable 5 only.
Which has the bigger context window, Aion 3.5 or Claude Fable 5?
Claude Fable 5, with 1M tokens against 262K.
Has any benchmark tested both Aion 3.5 and Claude Fable 5?
No benchmark has tested both yet. Aion 3.5 has none yet; Claude Fable 5 on LiveBench coding, LMArena WebDev and AA Coding Index. Compare them on price and context instead. Data as of October 22, 2026.