Claude Fable 5 vs DeepSeek V4.1 Flash 1017
Updated October 21, 2026. 29 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Claude Fable 5 and DeepSeek V4.1 Flash 1017 are level for coding, 82.1 against 83.3 on the Vibe Coding Index, so price and context decide.
Pick Claude Fable 5 when what matters is LiveBench coding or Terminal-Bench 4 (Vals AI), where it leads. Pick DeepSeek V4.1 Flash 1017 when output tokens cost 83.3x less, or when the context window is larger, 1.05M against 1M tokens.
- Shared results
- 29
- Claude Fable 5 only
- 97
- DeepSeek V4.1 Flash 1017 only
- 3
- Like-for-like categories
- 6 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
No call
Level: 82.1 against 83.3, inside 2 points.
2 benchmarks behind each score
Intelligence
AA Intelligence Index
Claude Fable 5
Claude Fable 5 leads, 49.6 against 39.5.
Same board, both measured
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
DeepSeek V4.1 Flash 1017
DeepSeek V4.1 Flash 1017 leads, 1312 against 1296.
Same board, both measured
General
Vals Index
No call
Only DeepSeek V4.1 Flash 1017 has a Vals Index result, 61.3%.
Directional only
Long documents
Listed context window
DeepSeek V4.1 Flash 1017
DeepSeek V4.1 Flash 1017 takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
DeepSeek V4.1 Flash 1017
Claude Fable 5 $0.035, DeepSeek V4.1 Flash 1017 $0.0004 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
- Claude Fable 5 82.1 from 2 benchmarks, DeepSeek V4.1 Flash 1017 83.3 from 2 benchmarks.
- Widest category
- Intelligence, 10.1 points apart on average over 1 shared benchmark.
- Widest single gap
- LiveBench browser: Claude Fable 5 92.0% against DeepSeek V4.1 Flash 1017 76.0%, 16.0 points apart on a 0 to 100 scale.
- Output price
- Claude Fable 5 $50.00 against DeepSeek V4.1 Flash 1017 $0.60 per million output tokens, 83.3x apart.
- Context window
- Claude Fable 5 takes 1M tokens, DeepSeek V4.1 Flash 1017 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 | Bars | DeepSeek V4.1 Flash 1017 | Ties |
|---|---|---|---|---|
| Coding | 6 | 3 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 5 | 2 | ||
| Reasoning | 2 | 0 | ||
| Web design | 3 | 5 | ||
| General | 1 | 1 | ||
| All shared boards | 18 | 11 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index63
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| LiveBench coding | 98.3% | 96.0% | Claude Fable 5 |
| LMArena WebDev | 1624 | 1664 | DeepSeek V4.1 Flash 1017 |
| AA Coding Index | 76.5 | Not measured | Only Claude Fable 5 measured |
| LiveCodeBench (Vals AI) | 89.8% | Not measured | Only Claude Fable 5 measured |
| SWE-bench Verified (Vals AI) | 95.0% | Not measured | Only Claude Fable 5 measured |
| Terminal-Bench 4 (Vals AI) | 41.4% | 31.8% | Claude Fable 5 |
| Vibe Code Bench (Vals AI) | 90.3% | 87.7% | Claude Fable 5 |
| Code migration (Vals AI) | 55.1% | 44.2% | Claude Fable 5 |
| ProgramBench (Vals AI) | 2.0% | Not measured | Only Claude Fable 5 measured |
| Terminal-Bench 2.1 (Vals AI) | 80.5% | Not measured | Only Claude Fable 5 measured |
| SciCode | 61.0% | 55.9% | Claude Fable 5 |
| Terminal-Bench Hard (Artificial Analysis run) | 62.9% | Not measured | Only Claude Fable 5 measured |
| FrontierCode | 53.5% | Not measured | Only Claude Fable 5 measured |
| FrontierSWE | 47.0% | Not measured | Only Claude Fable 5 measured |
| GSO-Bench | 78.4% | Not measured | Only Claude Fable 5 measured |
| WeirdML | 91.9% | Not measured | Only Claude Fable 5 measured |
| MirrorCode | 63.9% | Not measured | Only Claude Fable 5 measured |
| ALE-Bench | 2041.3 | 1622.0 | Claude Fable 5 |
| LMArena Text: coding | 1518 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: software and IT | 1513 | Not measured | Only Claude Fable 5 measured |
| LMArena WebDev: React | 1631 | 1667 | DeepSeek V4.1 Flash 1017 |
| LMArena WebDev: HTML | 1651 | 1687 | DeepSeek V4.1 Flash 1017 |
| LMArena WebDev: from an image | 1623 | Not measured | Only Claude Fable 5 measured |
| Neither model has a result on the other 15 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| AA Intelligence Index | 49.6 | 39.5 | Claude Fable 5 |
| Epoch Capabilities Index | 163.4 | Not measured | Only Claude Fable 5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index52
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| AA Agentic Index | 50.7 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building web apps | 1261 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building full-stack apps | 1280 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building mobile apps | 1264 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building Android apps | 1289 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building Godot games | 1292 | Not measured | Only Claude Fable 5 measured |
| Design Arena: agents building games | 1285 | Not measured | Only Claude Fable 5 measured |
| Design Arena: HTML slides | 1277 | Not measured | Only Claude Fable 5 measured |
| Design Arena: PowerPoint slides | 1295 | Not measured | Only Claude Fable 5 measured |
| Design Arena: spreadsheets | Not measured | 1238 | Only DeepSeek V4.1 Flash 1017 measured |
| LiveBench research | 86.9% | 79.5% | Claude Fable 5 |
| LiveBench browser | 92.0% | 76.0% | Claude Fable 5 |
| LiveBench long agentic | 53.2% | 50.9% | Claude Fable 5 |
| Finance Agent (Vals AI) | 56.3% | 57.0% | DeepSeek V4.1 Flash 1017 |
| Tax Agent Bench (Vals AI) | 38.3% | 44.4% | DeepSeek V4.1 Flash 1017 |
| Legal Research Bench (Vals AI) | 49.5% | 45.2% | Claude Fable 5 |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 14.2% | Only DeepSeek V4.1 Flash 1017 measured |
| Excel Modeling Benchmark (Vals AI) | 73.7% | 61.8% | Claude Fable 5 |
| Terminal-Bench-Science (Vals AI) | 15.7% | Not measured | Only Claude Fable 5 measured |
| τ²-Bench Telecom | 98.5% | Not measured | Only Claude Fable 5 measured |
| APEX-Agents | 63.6% | Not measured | Only Claude Fable 5 measured |
| Remote Labor Index | 16.1% | Not measured | Only Claude Fable 5 measured |
| PostTrainBench | 41.8% | Not measured | Only Claude Fable 5 measured |
| Vending-Bench 2 | $5,680 | Not measured | Only Claude Fable 5 measured |
| LMArena Search | 1229 | Not measured | Only Claude Fable 5 measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| GPQA Diamond | 93.2% | Not measured | Only Claude Fable 5 measured |
| LiveBench reasoning | 89.7% | 89.1% | Claude Fable 5 |
| MMMU Pro (Vals AI) | 89.3% | Not measured | Only Claude Fable 5 measured |
| GPQA Diamond (Artificial Analysis run) | 92.6% | Not measured | Only Claude Fable 5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 55.5% | 43.3% | Claude Fable 5 |
| GPQA Diamond (Epoch AI run) | 85.9% | Not measured | Only Claude Fable 5 measured |
| ARC-AGI | 98.5% | Not measured | Only Claude Fable 5 measured |
| ARC-AGI-2 | 89.2% | Not measured | Only Claude Fable 5 measured |
| SimpleBench | 81.9% | Not measured | Only Claude Fable 5 measured |
| Chess puzzles | 47.0% | Not measured | Only Claude Fable 5 measured |
| Mystery game puzzles | 52.0% | Not measured | Only Claude Fable 5 measured |
| EBR-bench | 39.5% | Not measured | Only Claude Fable 5 measured |
| LMArena Text: hard prompts | 1507 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: expert | 1534 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: hard prompts in English | 1509 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: diagrams | 1357 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: homework | 1361 | Not measured | Only Claude Fable 5 measured |
| Neither model has a result on the other 4 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only Claude Fable 5 measured |
| FrontierMath, tiers 1 to 3 | 87.0% | Not measured | Only Claude Fable 5 measured |
| FrontierMath, tier 4 | 90.2% | Not measured | Only Claude Fable 5 measured |
| ProofBench | 95.0% | Not measured | Only Claude Fable 5 measured |
| LMArena Text: math | 1516 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: mathematical work | 1515 | Not measured | 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 index11 boards, none shared
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| MMLU Pro | 91.5% | Not measured | Only Claude Fable 5 measured |
| LegalBench (Vals AI) | 88.6% | Not measured | Only Claude Fable 5 measured |
| CorpFin (Vals AI) | 71.8% | Not measured | Only Claude Fable 5 measured |
| TaxEval (Vals AI) | 76.9% | Not measured | Only Claude Fable 5 measured |
| MortgageTax (Vals AI) | 68.9% | Not measured | Only Claude Fable 5 measured |
| MedCode (Vals AI) | 56.1% | Not measured | Only Claude Fable 5 measured |
| SimpleQA Verified | 70.7% | Not measured | Only Claude Fable 5 measured |
| LMArena Text: science | 1506 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: medicine and healthcare | 1480 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: legal and government | 1498 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: business and finance | 1480 | Not measured | Only Claude Fable 5 measured |
| Neither model has a result on the other 6 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index35
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| Design Arena: websites | 1296 | 1312 | DeepSeek V4.1 Flash 1017 |
| Design Arena: UI components | 1318 | 1305 | Claude Fable 5 |
| Design Arena: game dev | 1336 | 1365 | DeepSeek V4.1 Flash 1017 |
| Design Arena: data viz | 1304 | 1330 | DeepSeek V4.1 Flash 1017 |
| Design Arena: 3D | 1319 | 1368 | DeepSeek V4.1 Flash 1017 |
| Design Arena: all code categories | 1310 | 1335 | DeepSeek V4.1 Flash 1017 |
| Design Arena: SVG | 1302 | Not measured | Only Claude Fable 5 measured |
| Design Arena: ASCII art | 1328 | 1244 | Claude Fable 5 |
| LiveBench design | 84.7% | 83.4% | Claude Fable 5 |
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | Leader |
|---|---|---|---|
| Vals Index | Not measured | 61.3% | Only DeepSeek V4.1 Flash 1017 measured |
| LiveBench data analysis | 80.5% | 79.5% | Claude Fable 5 |
| Public Benefits Bench (Vals AI) | 70.4% | Not measured | Only Claude Fable 5 measured |
| SAGE (Vals AI) | 51.9% | Not measured | Only Claude Fable 5 measured |
| MedScribe (Vals AI) | 88.5% | Not measured | Only Claude Fable 5 measured |
| Vals Multimodal Index | 74.2% | Not measured | Only Claude Fable 5 measured |
| IFBench | 63.5% | Not measured | Only Claude Fable 5 measured |
| Long context reasoning (AA-LCR) | 82.3% | 82.7% | DeepSeek V4.1 Flash 1017 |
| DTBench | 98.4% | Not measured | Only Claude Fable 5 measured |
| LMCA | 61.2% | Not measured | Only Claude Fable 5 measured |
| Surface Evolver Bench | 95.0% | Not measured | Only Claude Fable 5 measured |
| Furniture assembly | 35.8% | Not measured | Only Claude Fable 5 measured |
| LMArena Text | 1491 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: instruction following | 1502 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: creative writing | 1494 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision | 1325 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: English | 1498 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: non-English | 1482 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Chinese | 1543 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: German | 1486 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Japanese | 1504 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Korean | 1487 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: French | 1505 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Spanish | 1498 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Russian | 1503 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: Polish | 1494 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: multi-turn | 1504 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: longer queries | 1510 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: writing and language | 1501 | Not measured | Only Claude Fable 5 measured |
| LMArena Text: entertainment and media | 1482 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: English | 1323 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: Chinese | 1373 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: reading text | 1337 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: humor | 1341 | Not measured | Only Claude Fable 5 measured |
| LMArena Vision: creative writing | 1338 | Not measured | Only Claude Fable 5 measured |
| LMArena Document | 1496 | Not measured | Only Claude Fable 5 measured |
| Neither model has a result on the other 10 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Fable 5 | DeepSeek V4.1 Flash 1017 | 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
DeepSeek V4.1 Flash 1017 costs less
Repository review
50K input + 3K output tokens
DeepSeek V4.1 Flash 1017 costs less
Agent loop
200K input + 10K output tokens
DeepSeek V4.1 Flash 1017 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 | DeepSeek V4.1 Flash 1017 |
|---|---|---|
| Maker | Anthropic | DeepSeek |
| Weights | No public weights listed | Open weights |
| Released | June 9, 2026 | October 17, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $10.00 | $0.15 |
| Output $/Mtok | $50.00 | $0.60 |
| Coding index | 82.1 | 83.3 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $2.16 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Fable 5 better than DeepSeek V4.1 Flash 1017 for coding?
Claude Fable 5 and DeepSeek V4.1 Flash 1017 are level for coding, 82.1 against 83.3 on the Vibe Coding Index, so price and context decide. Pick Claude Fable 5 when what matters is LiveBench coding or Terminal-Bench 4 (Vals AI), where it leads. Pick DeepSeek V4.1 Flash 1017 when output tokens cost 83.3x less, or when the context window is larger, 1.05M against 1M tokens.
Which is cheaper, Claude Fable 5 or DeepSeek V4.1 Flash 1017?
Claude Fable 5 costs $10.00 per million input tokens and $50.00 per million output tokens; DeepSeek V4.1 Flash 1017 costs $0.15 and $0.60. Cost per solved task is known for Claude Fable 5 only.
Which has the bigger context window, Claude Fable 5 or DeepSeek V4.1 Flash 1017?
DeepSeek V4.1 Flash 1017, with 1.05M tokens against 1M.
How many benchmarks is the Claude Fable 5 vs DeepSeek V4.1 Flash 1017 comparison based on?
29 benchmarks have a result for both models as of October 21, 2026. Claude Fable 5's coding index rests on 2 independent benchmarks and DeepSeek V4.1 Flash 1017's on 2. Where only one model has a result, the page says so instead of naming a winner.