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Claude Fable 5.1 vs Claude Opus 4.6

Claude Fable 5.1 leads Claude Opus 4.6 on coding, 84.2 to 57.2 on the Vibe Coding Index, and Claude Opus 4.6 costs 2.0x less per output token ($25.00 vs $50.00 per million). Updated October 22, 2026; 86 benchmarks have a result for both.

Replace Claude Fable 5.1 Replace Claude Opus 4.6
Claude Fable 5.1Anthropic
Coding
84.2
Overall
84.7
Output $/M
$50.00
74
Claude Opus 4.6Anthropic
Coding
57.2
Overall
66.0
Output $/M
$25.00
11
vs boards won of 86 shared, 1 tied

Claude Fable 5.1 or Claude Opus 4.6: which to pick

Pick Claude Fable 5.1 for coding: it scores 84.2 on the Vibe Coding Index against 57.2 for Claude Opus 4.6.

Pick Claude Opus 4.6 for output tokens 2.0x cheaper ($25.00 vs $50.00 per million) and work measured by LMArena Text: coding or Vending-Bench 2, where it leads.

Model AClaude Fable 5.1Anthropic84.2/1005 independent benchmarksNo cost per solved taskModel BClaude Opus 4.6Anthropic57.2/1004 independent benchmarks$1.56 per solved task
Shared results
86
Claude Fable 5.1 only
38
Claude Opus 4.6 only
24
Like-for-like categories
8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

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.

At a glance

Coding index
Claude Fable 5.1 84.2 from 5 benchmarks, Claude Opus 4.6 57.2 from 4 benchmarks.
Widest category
Math, 24.2 points apart on average over 6 shared benchmarks.
Widest single gap
FrontierMath, tier 4: Claude Fable 5.1 87.8% against Claude Opus 4.6 26.8%, 61.0 points apart on a 0 to 100 scale.
Output price
Claude Fable 5.1 $50.00 against Claude Opus 4.6 $25.00 per million output tokens, 2.0x apart.
Context window
Both take 1M tokens.

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.

Boards won, where both have a result
CategoryClaude Fable 5.1BarsClaude Opus 4.6Ties
Coding101
Intelligence20
Agentic work51
Reasoning131
Math60
Knowledge811 tie
Web design80
General227
All shared boards74111 tie
CodingLike-for-likeSix of these boards feed the Vibe Coding Index101
Coding benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
SWE-bench VerifiedNot measured75.6%Only Claude Opus 4.6 measured
SWE-bench MultilingualNot measured72.0%Only Claude Opus 4.6 measured
LiveBench coding97.7%Not measuredOnly Claude Fable 5.1 measured
LMArena WebDev17431547Claude Fable 5.1
AA Coding Index81.6Not measuredOnly Claude Fable 5.1 measured
LiveCodeBench (Vals AI)90.5%84.7%Claude Fable 5.1
SWE-bench Verified (Vals AI)Not measured78.2%Only Claude Opus 4.6 measured
Terminal-Bench 4 (Vals AI)58.1%Not measuredOnly Claude Fable 5.1 measured
Vibe Code Bench (Vals AI)90.3%57.6%Claude Fable 5.1
Code migration (Vals AI)54.6%Not measuredOnly Claude Fable 5.1 measured
ProgramBench (Vals AI)7.0%Not measuredOnly Claude Fable 5.1 measured
IOI (Vals AI)90.8%Not measuredOnly Claude Fable 5.1 measured
Terminal-Bench 2.1 (Vals AI)85.0%Not measuredOnly Claude Fable 5.1 measured
SWE-bench Multimodal (Vals AI)61.3%Not measuredOnly Claude Fable 5.1 measured
Vibe Code Bench 1-100 (Vals AI)28.0%Not measuredOnly Claude Fable 5.1 measured
SkillsBench (Vals AI)61.5%Not measuredOnly Claude Fable 5.1 measured
CyberBench (Vals AI)70.4%Not measuredOnly Claude Fable 5.1 measured
SciCode63.1%Not measuredOnly Claude Fable 5.1 measured
Terminal-Bench Hard (Artificial Analysis run)Not measured48.5%Only Claude Opus 4.6 measured
Terminal-BenchNot measured79.8%Only Claude Opus 4.6 measured
FrontierCode50.9%26.6%Claude Fable 5.1
FrontierSWE56.3%Not measuredOnly Claude Fable 5.1 measured
GSO-Bench88.2%41.2%Claude Fable 5.1
WeirdML92.9%78.0%Claude Fable 5.1
MirrorCode73.3%Not measuredOnly Claude Fable 5.1 measured
CybenchNot measured93.0%Only Claude Opus 4.6 measured
ALE-Bench2143.2Not measuredOnly Claude Fable 5.1 measured
LMArena Text: coding15321534Claude Opus 4.6
LMArena Text: software and IT15301527Claude Fable 5.1
LMArena WebDev: React17921539Claude Fable 5.1
LMArena WebDev: HTML16841559Claude Fable 5.1
LMArena WebDev: from an image17221543Claude Fable 5.1
Neither model has a result on the other 7 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
AA Intelligence Index53.431.9Claude Fable 5.1
Epoch Capabilities Index166.5155.7Claude Fable 5.1
Agentic workLike-for-likePublic boards, shown as published, kept out of the index51
Agentic work benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
AA Agentic Index57.9Not measuredOnly Claude Fable 5.1 measured
Design Arena: agents building web apps13181206Claude Fable 5.1
Design Arena: agents building full-stack apps13261220Claude Fable 5.1
Design Arena: agents building mobile apps12671207Claude Fable 5.1
Design Arena: agents building Android appsNot measured1197Only Claude Opus 4.6 measured
Design Arena: agents building Godot games1327Not measuredOnly Claude Fable 5.1 measured
Design Arena: agents building gamesNot measured1212Only Claude Opus 4.6 measured
Design Arena: PowerPoint slides1305Not measuredOnly Claude Fable 5.1 measured
Design Arena: spreadsheets1380Not measuredOnly Claude Fable 5.1 measured
LiveBench research82.0%Not measuredOnly Claude Fable 5.1 measured
LiveBench browser100.0%Not measuredOnly Claude Fable 5.1 measured
LiveBench long agentic80.8%Not measuredOnly Claude Fable 5.1 measured
SREBench (Vals AI)22.9%Not measuredOnly Claude Fable 5.1 measured
Finance Agent (Vals AI)58.9%Not measuredOnly Claude Fable 5.1 measured
Tax Agent Bench (Vals AI)49.2%Not measuredOnly Claude Fable 5.1 measured
Legal Research Bench (Vals AI)55.3%Not measuredOnly Claude Fable 5.1 measured
Excel Modeling Benchmark (Vals AI)76.7%Not measuredOnly Claude Fable 5.1 measured
Terminal-Bench-Science (Vals AI)40.0%Not measuredOnly Claude Fable 5.1 measured
Time Horizon Index (Vals AI)63.3%Not measuredOnly Claude Fable 5.1 measured
CUA-bench (Vals AI)13.2%Not measuredOnly Claude Fable 5.1 measured
Robo-bench (Vals AI)5.8%Not measuredOnly Claude Fable 5.1 measured
τ²-Bench TelecomNot measured92.1%Only Claude Opus 4.6 measured
APEX-Agents68.6%46.3%Claude Fable 5.1
METR time horizonsNot measured78.9%Only Claude Opus 4.6 measured
Remote Labor Index17.9%4.2%Claude Fable 5.1
DeepResearch BenchNot measured55.3%Only Claude Opus 4.6 measured
SpireClimb2.0%Not measuredOnly Claude Fable 5.1 measured
Vending-Bench 2$5,422$8,018Claude Opus 4.6
LMArena Search1246Not measuredOnly Claude Fable 5.1 measured
Neither model has a result on the other 12 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index131
Reasoning benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
GPQA Diamond93.4%89.7%Claude Fable 5.1
LiveBench reasoning91.7%Not measuredOnly Claude Fable 5.1 measured
MysteryMechanism (Vals AI)47.8%Not measuredOnly Claude Fable 5.1 measured
MMMU Pro (Vals AI)90.6%83.9%Claude Fable 5.1
GPQA Diamond (Artificial Analysis run)93.7%89.6%Claude Fable 5.1
Humanity's Last Exam (Artificial Analysis run)59.1%39.9%Claude Fable 5.1
GPQA Diamond (Epoch AI run)Not measured90.5%Only Claude Opus 4.6 measured
ARC-AGI97.5%94.0%Claude Fable 5.1
ARC-AGI-290.0%69.2%Claude Fable 5.1
SimpleBenchNot measured67.6%Only Claude Opus 4.6 measured
Chess puzzles48.0%21.0%Claude Fable 5.1
Mystery game puzzles58.0%25.0%Claude Fable 5.1
EBR-bench57.1%12.7%Claude Fable 5.1
LMArena Text: hard prompts15281525Claude Fable 5.1
LMArena Text: expert15441544Claude Fable 5.1
LMArena Text: hard prompts in English15221530Claude Opus 4.6
LMArena Vision: diagrams13431340Claude Fable 5.1
LMArena Vision: homework13451337Claude Fable 5.1
Kagi LLM BenchmarkNot measured83.6%Only Claude Opus 4.6 measured
Neither model has a result on the other 3 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index60
Math benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
AIMENot measured95.6%Only Claude Opus 4.6 measured
OTIS Mock AIME100.0%94.4%Claude Fable 5.1
FrontierMath, tiers 1 to 390.2%66.0%Claude Fable 5.1
FrontierMath, tier 487.8%26.8%Claude Fable 5.1
ProofBench100.0%50.0%Claude Fable 5.1
LMArena Text: math15311518Claude Fable 5.1
LMArena Text: mathematical work15411525Claude Fable 5.1
Neither model has a result on the other 6 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index81
Knowledge benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
MMLU Pro92.4%89.1%Claude Fable 5.1
LegalBench (Vals AI)88.5%85.3%Claude Fable 5.1
CaseLaw (Vals AI)Not measured62.1%Only Claude Opus 4.6 measured
CorpFin (Vals AI)Not measured67.0%Only Claude Opus 4.6 measured
TaxEval (Vals AI)76.0%76.0%Tie
MortgageTax (Vals AI)70.8%68.5%Claude Fable 5.1
MedQA (Vals AI)Not measured95.4%Only Claude Opus 4.6 measured
MedCode (Vals AI)53.5%49.1%Claude Fable 5.1
SimpleQA Verified70.8%47.0%Claude Fable 5.1
LMArena Text: science15321519Claude Fable 5.1
LMArena Text: medicine and healthcare15311504Claude Fable 5.1
LMArena Text: legal and government15141512Claude Fable 5.1
LMArena Text: business and finance14931497Claude Opus 4.6
FACTS Benchmark SuiteNot measured41.5%Only Claude Opus 4.6 measured
Neither model has a result on the other 4 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index80
Web design benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
Design Arena: websites13121291Claude Fable 5.1
Design Arena: UI components13361281Claude Fable 5.1
Design Arena: game dev13811277Claude Fable 5.1
Design Arena: data viz13441279Claude Fable 5.1
Design Arena: 3D13921273Claude Fable 5.1
Design Arena: all code categories13351288Claude Fable 5.1
Design Arena: SVG13001227Claude Fable 5.1
Design Arena: ASCII art13231255Claude Fable 5.1
LiveBench design83.4%Not measuredOnly Claude Fable 5.1 measured
GeneralLike-for-likePublic boards, shown as published, kept out of the index227
General benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
LiveBench data analysis80.3%Not measuredOnly Claude Fable 5.1 measured
Public Benefits Bench (Vals AI)74.9%Not measuredOnly Claude Fable 5.1 measured
SAGE (Vals AI)48.5%51.6%Claude Opus 4.6
MedScribe (Vals AI)91.3%86.7%Claude Fable 5.1
IFBenchNot measured53.1%Only Claude Opus 4.6 measured
Long context reasoning (AA-LCR)85.3%78.0%Claude Fable 5.1
DTBench97.6%91.2%Claude Fable 5.1
LMCA65.5%55.8%Claude Fable 5.1
CL-benchNot measured20.7%Only Claude Opus 4.6 measured
Furniture assembly70.0%28.3%Claude Fable 5.1
CL-bench LifeNot measured17.0%Only Claude Opus 4.6 measured
LMArena Text15121501Claude Fable 5.1
LMArena Text: instruction following15181521Claude Opus 4.6
LMArena Text: creative writing15091505Claude Fable 5.1
LMArena Vision13191316Claude Fable 5.1
LMArena Text: English15061511Claude Opus 4.6
LMArena Text: non-English15081488Claude Fable 5.1
LMArena Text: Chinese15841551Claude Fable 5.1
LMArena Text: German14991500Claude Opus 4.6
LMArena Text: Japanese15621488Claude Fable 5.1
LMArena Text: Korean15171464Claude Fable 5.1
LMArena Text: French15231512Claude Fable 5.1
LMArena Text: Spanish15201510Claude Fable 5.1
LMArena Text: Russian15201497Claude Fable 5.1
LMArena Text: Polish15251499Claude Fable 5.1
LMArena Text: multi-turn14931511Claude Opus 4.6
LMArena Text: longer queries15241518Claude Fable 5.1
LMArena Text: writing and language15101502Claude Fable 5.1
LMArena Text: entertainment and media14971492Claude Fable 5.1
LMArena Vision: English13131324Claude Opus 4.6
LMArena Vision: Chinese13911370Claude Fable 5.1
LMArena Vision: reading text13271326Claude Fable 5.1
LMArena Vision: humor13181314Claude Fable 5.1
LMArena Vision: recognizing thingsNot measured1274Only Claude Opus 4.6 measured
LMArena Vision: creative writing13301331Claude Opus 4.6
LMArena DocumentNot measured1507Only Claude Opus 4.6 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
Image generation benchmarks for Claude Fable 5.1 and Claude Opus 4.6
BenchmarkClaude Fable 5.1Claude Opus 4.6Leader
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
Claude Opus 4.6$0.018Fits in one request

Claude Opus 4.6 costs less

Repository review

50K input + 3K output tokens

Claude Fable 5.1$0.650Fits in one request
Claude Opus 4.6$0.325Fits in one request

Claude Opus 4.6 costs less

Agent loop

200K input + 10K output tokens

Claude Fable 5.1$2.50Fits in one request
Claude Opus 4.6$1.25Fits in one request

Claude Opus 4.6 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.

Specifications of Claude Fable 5.1 and Claude Opus 4.6
SpecificationAnthropic Claude Fable 5.1Anthropic Claude Opus 4.6
MakerAnthropicAnthropic
WeightsNo public weights listedNo public weights listed
ReleasedSeptember 1, 2026February 4, 2026
Context window1M1M
Input $/Mtok$10.00$5.00
Output $/Mtok$50.00$25.00
Coding index84.257.2
Independent measurements behind it54
Cost per solved taskNot computable$1.56
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Fable 5.1 better than Claude Opus 4.6 for coding?

Pick Claude Fable 5.1 for coding: it scores 84.2 on the Vibe Coding Index against 57.2 for Claude Opus 4.6. Pick Claude Opus 4.6 for output tokens 2.0x cheaper ($25.00 vs $50.00 per million) and work measured by LMArena Text: coding or Vending-Bench 2, where it leads.

Which is cheaper, Claude Fable 5.1 or Claude Opus 4.6?

Claude Fable 5.1 costs $10.00 per million input tokens and $50.00 per million output tokens; Claude Opus 4.6 costs $5.00 and $25.00. Cost per solved task is known for Claude Opus 4.6 only.

Which has the bigger context window, Claude Fable 5.1 or Claude Opus 4.6?

Neither: both take 1M tokens.

How many benchmarks is the Claude Fable 5.1 vs Claude Opus 4.6 comparison based on?

86 benchmarks have a result for both models as of October 22, 2026. Claude Fable 5.1's coding index rests on 5 independent benchmarks and Claude Opus 4.6's on 4. Where only one model has a result, the page says so instead of naming a winner.

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