Claude Fable 5.1 vs Hy4 preview
Updated October 21, 2026. 21 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
vs boards won of 21 shared
Decision reading
Pick Claude Fable 5.1 for coding: it scores 89.1 on the Vibe Coding Index against 61.6 for Hy4 preview.
Pick Hy4 preview when output tokens cost 20.0x less, or when the context window is larger, 1.05M against 1M tokens.
Model AClaude Fable 5.1Anthropic89.1/1002 independent benchmarksNo cost per solved taskModel BHy4 previewTencent61.6/1001 independent benchmarkNo cost per solved task
- Shared results
- 21
- Claude Fable 5.1 only
- 103
- Hy4 preview only
- 3
- Like-for-like categories
- 5 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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, four public coding benchmarks
Claude Fable 5.1
Claude Fable 5.1 scores 89.1 against 61.6.
2 and 1 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Claude Fable 5.1 has a AA Intelligence Index result, 53.4.
Directional only
Agentic work
AA Agentic Index
No call
Only Claude Fable 5.1 has a AA Agentic Index result, 57.9.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Fable 5.1 has a GPQA Diamond result, 93.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Fable 5.1 has a MMLU Pro result, 92.4%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Fable 5.1 has a Design Arena: websites result, 1313.
Directional only
General
Vals Index
No call
Only Hy4 preview has a Vals Index result, 53.2%.
Directional only
Long documents
Listed context window
Hy4 preview
Hy4 preview takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Hy4 preview
Claude Fable 5.1 $0.035, Hy4 preview $0.0021 per turn.
List prices
At a glance
- Coding index
- Claude Fable 5.1 89.1 from 2 benchmarks, Hy4 preview 61.6 from 1 benchmark.
- Widest category
- Math, 25.0 points apart on average over 1 shared benchmark.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Claude Fable 5.1 58.1% against Hy4 preview 8.1%, 50.0 points apart on a 0 to 100 scale.
- Output price
- Claude Fable 5.1 $50.00 against Hy4 preview $2.501 per million output tokens, 20.0x apart.
- Context window
- Claude Fable 5.1 takes 1M tokens, Hy4 preview 1.05M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Claude Fable 5.1 | Bars | Hy4 preview | Ties |
|---|---|---|---|---|
| Coding | 10 | 0 | ||
| Agentic work | 6 | 0 | ||
| Math | 1 | 0 | ||
| Knowledge | 2 | 0 | ||
| General | 2 | 0 | ||
| All shared boards | 21 | 0 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index100
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| LiveBench coding | 97.7% | Not measured | Only Claude Fable 5.1 measured |
| LMArena WebDev | 1743 | 1631 | Claude Fable 5.1 |
| AA Coding Index | 81.6 | Not measured | Only Claude Fable 5.1 measured |
| LiveCodeBench (Vals AI) | 90.5% | Not measured | Only Claude Fable 5.1 measured |
| Terminal-Bench 4 (Vals AI) | 58.1% | 8.1% | Claude Fable 5.1 |
| Vibe Code Bench (Vals AI) | 90.3% | 77.5% | Claude Fable 5.1 |
| Code migration (Vals AI) | 54.6% | 47.4% | Claude Fable 5.1 |
| ProgramBench (Vals AI) | 7.0% | 0.0% | Claude Fable 5.1 |
| IOI (Vals AI) | 90.8% | 59.3% | Claude Fable 5.1 |
| Terminal-Bench 2.1 (Vals AI) | 85.0% | 55.1% | Claude Fable 5.1 |
| SWE-bench Multimodal (Vals AI) | 61.3% | Not measured | Only Claude Fable 5.1 measured |
| Vibe Code Bench 1-100 (Vals AI) | 28.0% | Not measured | Only Claude Fable 5.1 measured |
| SkillsBench (Vals AI) | 61.5% | Not measured | Only Claude Fable 5.1 measured |
| CyberBench (Vals AI) | 70.4% | 65.4% | Claude Fable 5.1 |
| SciCode | 63.1% | Not measured | Only Claude Fable 5.1 measured |
| FrontierCode | 50.9% | Not measured | Only Claude Fable 5.1 measured |
| FrontierSWE | 56.3% | Not measured | Only Claude Fable 5.1 measured |
| GSO-Bench | 88.2% | Not measured | Only Claude Fable 5.1 measured |
| WeirdML | 92.9% | Not measured | Only Claude Fable 5.1 measured |
| MirrorCode | 73.3% | Not measured | Only Claude Fable 5.1 measured |
| ALE-Bench | 2143.2 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: coding | 1532 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: software and IT | 1530 | Not measured | Only Claude Fable 5.1 measured |
| LMArena WebDev: React | 1792 | 1653 | Claude Fable 5.1 |
| LMArena WebDev: HTML | 1684 | 1620 | Claude Fable 5.1 |
| LMArena WebDev: from an image | 1722 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 12 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| AA Intelligence Index | 53.4 | Not measured | Only Claude Fable 5.1 measured |
| Epoch Capabilities Index | 166.5 | Not measured | Only Claude Fable 5.1 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| AA Agentic Index | 57.9 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building web apps | 1318 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building full-stack apps | 1326 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building mobile apps | 1267 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: agents building Godot games | 1327 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: PowerPoint slides | 1328 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: spreadsheets | 1374 | Not measured | Only Claude Fable 5.1 measured |
| LiveBench research | 82.0% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench browser | 100.0% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench long agentic | 80.8% | Not measured | Only Claude Fable 5.1 measured |
| SREBench (Vals AI) | 22.9% | 2.3% | Claude Fable 5.1 |
| Finance Agent (Vals AI) | 58.9% | 55.1% | Claude Fable 5.1 |
| Tax Agent Bench (Vals AI) | 49.2% | 32.6% | Claude Fable 5.1 |
| Legal Research Bench (Vals AI) | 55.3% | 45.2% | Claude Fable 5.1 |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 8.8% | Only Hy4 preview measured |
| Excel Modeling Benchmark (Vals AI) | 76.7% | 58.1% | Claude Fable 5.1 |
| BioMysteryBench (Vals AI) | Not measured | 69.3% | Only Hy4 preview measured |
| Terminal-Bench-Science (Vals AI) | 40.0% | 1.4% | Claude Fable 5.1 |
| Time Horizon Index (Vals AI) | 63.3% | Not measured | Only Claude Fable 5.1 measured |
| CUA-bench (Vals AI) | 13.2% | Not measured | Only Claude Fable 5.1 measured |
| Robo-bench (Vals AI) | 5.8% | Not measured | Only Claude Fable 5.1 measured |
| APEX-Agents | 68.6% | Not measured | Only Claude Fable 5.1 measured |
| Remote Labor Index | 17.9% | Not measured | Only Claude Fable 5.1 measured |
| SpireClimb | 2.0% | Not measured | Only Claude Fable 5.1 measured |
| Vending-Bench 2 | $5,422 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Search | 1246 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 13 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index16 boards, none shared
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| GPQA Diamond | 93.4% | Not measured | Only Claude Fable 5.1 measured |
| LiveBench reasoning | 91.7% | Not measured | Only Claude Fable 5.1 measured |
| MysteryMechanism (Vals AI) | 47.8% | Not measured | Only Claude Fable 5.1 measured |
| MMMU Pro (Vals AI) | 90.6% | Not measured | Only Claude Fable 5.1 measured |
| GPQA Diamond (Artificial Analysis run) | 93.7% | Not measured | Only Claude Fable 5.1 measured |
| Humanity's Last Exam (Artificial Analysis run) | 59.1% | Not measured | Only Claude Fable 5.1 measured |
| ARC-AGI | 97.5% | Not measured | Only Claude Fable 5.1 measured |
| ARC-AGI-2 | 90.0% | Not measured | Only Claude Fable 5.1 measured |
| Chess puzzles | 48.0% | Not measured | Only Claude Fable 5.1 measured |
| Mystery game puzzles | 58.0% | Not measured | Only Claude Fable 5.1 measured |
| EBR-bench | 57.1% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: hard prompts | 1528 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: expert | 1544 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: hard prompts in English | 1522 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: diagrams | 1343 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: homework | 1345 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 5 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only Claude Fable 5.1 measured |
| FrontierMath, tiers 1 to 3 | 90.2% | Not measured | Only Claude Fable 5.1 measured |
| FrontierMath, tier 4 | 87.8% | Not measured | Only Claude Fable 5.1 measured |
| ProofBench | 100.0% | 75.0% | Claude Fable 5.1 |
| LMArena Text: math | 1531 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: mathematical work | 1541 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| MMLU Pro | 92.4% | Not measured | Only Claude Fable 5.1 measured |
| LegalBench (Vals AI) | 88.5% | 83.8% | Claude Fable 5.1 |
| TaxEval (Vals AI) | 76.0% | Not measured | Only Claude Fable 5.1 measured |
| MortgageTax (Vals AI) | 70.8% | Not measured | Only Claude Fable 5.1 measured |
| MedCode (Vals AI) | 53.5% | 43.3% | Claude Fable 5.1 |
| SimpleQA Verified | 70.8% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: science | 1532 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: medicine and healthcare | 1531 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: legal and government | 1514 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: business and finance | 1493 | Not measured | Only Claude Fable 5.1 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, none shared
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| Design Arena: websites | 1313 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: UI components | 1338 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: game dev | 1382 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: data viz | 1344 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: 3D | 1393 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: all code categories | 1336 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: SVG | 1301 | Not measured | Only Claude Fable 5.1 measured |
| Design Arena: ASCII art | 1324 | Not measured | Only Claude Fable 5.1 measured |
| LiveBench design | 83.4% | Not measured | Only Claude Fable 5.1 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| Vals Index | Not measured | 53.2% | Only Hy4 preview measured |
| LiveBench data analysis | 80.3% | Not measured | Only Claude Fable 5.1 measured |
| Public Benefits Bench (Vals AI) | 74.9% | 68.6% | Claude Fable 5.1 |
| SAGE (Vals AI) | 48.5% | Not measured | Only Claude Fable 5.1 measured |
| MedScribe (Vals AI) | 91.3% | 83.6% | Claude Fable 5.1 |
| Long context reasoning (AA-LCR) | 85.3% | Not measured | Only Claude Fable 5.1 measured |
| DTBench | 97.6% | Not measured | Only Claude Fable 5.1 measured |
| LMCA | 65.5% | Not measured | Only Claude Fable 5.1 measured |
| Furniture assembly | 70.0% | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text | 1512 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: instruction following | 1518 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: creative writing | 1509 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision | 1319 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: English | 1506 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: non-English | 1508 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Chinese | 1584 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: German | 1499 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Japanese | 1562 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Korean | 1517 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: French | 1523 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Spanish | 1520 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Russian | 1520 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: Polish | 1525 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: multi-turn | 1493 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: longer queries | 1524 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: writing and language | 1510 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Text: entertainment and media | 1497 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: English | 1313 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: Chinese | 1391 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: reading text | 1327 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: humor | 1318 | Not measured | Only Claude Fable 5.1 measured |
| LMArena Vision: creative writing | 1330 | Not measured | Only Claude Fable 5.1 measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Fable 5.1 | Hy4 preview | Leader |
|---|---|---|---|
| Neither model has a result on 5 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
Claude Fable 5.1$0.035Fits in one request
Hy4 preview$0.0021Fits in one request
Hy4 preview costs less
Repository review
50K input + 3K output tokens
Claude Fable 5.1$0.650Fits in one request
Hy4 preview$0.049Fits in one request
Hy4 preview costs less
Agent loop
200K input + 10K output tokens
Claude Fable 5.1$2.50Fits in one request
Hy4 preview$0.192Fits in one request
Hy4 preview 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 | Anthropic Claude Fable 5.1 | Tencent Hy4 preview |
|---|---|---|
| Maker | Anthropic | Tencent |
| Weights | No public weights listed | Open weights |
| Released | September 1, 2026 | August 28, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $10.00 | $0.834 |
| Output $/Mtok | $50.00 | $2.501 |
| Coding index | 89.1 | 61.6 |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Fable 5.1 better than Hy4 preview for coding?
Pick Claude Fable 5.1 for coding: it scores 89.1 on the Vibe Coding Index against 61.6 for Hy4 preview. Pick Hy4 preview when output tokens cost 20.0x less, or when the context window is larger, 1.05M against 1M tokens.
Which is cheaper, Claude Fable 5.1 or Hy4 preview?
Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Hy4 preview costs $0.834 and $2.501. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Fable 5.1 or Hy4 preview?
Hy4 preview, with 1.05M tokens against 1M.
How many benchmarks is the Claude Fable 5.1 vs Hy4 preview comparison based on?
21 benchmarks have a result for both models as of October 21, 2026. Claude Fable 5.1's coding index rests on 2 independent benchmarks and Hy4 preview's on 1. Where only one model has a result, the page says so instead of naming a winner.