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Claude Fable 5 vs GPT-5.5

Claude Fable 5 leads GPT-5.5 on coding, 79.3 to 71.3 on the Vibe Coding Index, and GPT-5.5 costs 1.7x less per output token ($30.00 vs $50.00 per million). Updated October 22, 2026; 123 benchmarks have a result for both.

Replace Claude Fable 5 Replace GPT-5.5
Claude Fable 5Anthropic
Coding
79.3
Overall
79.0
Output $/M
$50.00
112
GPT-5.5OpenAI
Coding
71.3
Overall
69.2
Output $/M
$30.00
9
vs boards won of 123 shared, 2 tied

Claude Fable 5 or GPT-5.5: which to pick

Pick Claude Fable 5 for coding: it scores 79.3 on the Vibe Coding Index against 71.3 for GPT-5.5.

Pick GPT-5.5 for output tokens 1.7x cheaper ($30.00 vs $50.00 per million) and a lower cost per solved task ($1.65 against $2.16).

Model AClaude Fable 5Anthropic79.3/1006 independent benchmarks$2.16 per solved taskModel BGPT-5.5OpenAI71.3/1005 independent benchmarks$1.65 per solved task
Shared results
123
Claude Fable 5 only
4
GPT-5.5 only
11
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 79.3 from 6 benchmarks, GPT-5.5 71.3 from 5 benchmarks.
Widest category
Agentic work, 15.7 points apart on average over 21 shared benchmarks.
Widest single gap
MirrorCode: Claude Fable 5 63.9% against GPT-5.5 10.0%, 53.9 points apart on a 0 to 100 scale.
Output price
Claude Fable 5 $50.00 against GPT-5.5 $30.00 per million output tokens, 1.7x apart.
Context window
Claude Fable 5 takes 1M tokens, GPT-5.5 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.

Boards won, where both have a result
CategoryClaude Fable 5BarsGPT-5.5Ties
Coding210
Intelligence20
Agentic work201
Reasoning1242 ties
Math60
Knowledge110
Web design90
General314
All shared boards11292 ties
CodingLike-for-likeSix of these boards feed the Vibe Coding Index210
Coding benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
LiveBench coding98.3%85.1%Claude Fable 5
LMArena WebDev16241513Claude Fable 5
AA Coding Index76.574.9Claude Fable 5
LiveCodeBench (Vals AI)89.8%85.3%Claude Fable 5
SWE-bench Verified (Vals AI)95.0%82.6%Claude Fable 5
Terminal-Bench 4 (Vals AI)41.4%Not measuredOnly Claude Fable 5 measured
Vibe Code Bench (Vals AI)90.3%69.8%Claude Fable 5
Code migration (Vals AI)55.1%45.2%Claude Fable 5
ProgramBench (Vals AI)2.0%0.5%Claude Fable 5
Terminal-Bench 2.1 (Vals AI)80.5%76.4%Claude Fable 5
SkillsBench (Vals AI)Not measured62.5%Only GPT-5.5 measured
SciCode61.0%56.1%Claude Fable 5
Terminal-Bench Hard (Artificial Analysis run)62.9%60.6%Claude Fable 5
Terminal-BenchNot measured84.7%Only GPT-5.5 measured
FrontierCode53.5%43.0%Claude Fable 5
FrontierSWE47.0%Not measuredOnly Claude Fable 5 measured
GSO-Bench78.4%40.2%Claude Fable 5
WeirdML91.9%84.9%Claude Fable 5
MirrorCode63.9%10.0%Claude Fable 5
ALE-Bench2041.31943.0Claude Fable 5
LMArena Text: coding15181494Claude Fable 5
LMArena Text: software and IT15131493Claude Fable 5
LMArena WebDev: React16311506Claude Fable 5
LMArena WebDev: HTML16511543Claude Fable 5
LMArena WebDev: from an image16231532Claude Fable 5
Neither model has a result on the other 14 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
AA Intelligence Index49.638.4Claude Fable 5
Epoch Capabilities Index163.4159.7Claude Fable 5
Agentic workLike-for-likePublic boards, shown as published, kept out of the index201
Agentic work benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
AA Agentic Index50.736.4Claude Fable 5
Design Arena: agents building web apps12611117Claude Fable 5
Design Arena: agents building full-stack apps12801089Claude Fable 5
Design Arena: agents building mobile apps12641142Claude Fable 5
Design Arena: agents building Android apps12841164Claude Fable 5
Design Arena: agents building Godot games12921173Claude Fable 5
Design Arena: agents building games12851179Claude Fable 5
Design Arena: HTML slides12271017Claude Fable 5
Design Arena: PowerPoint slides12701084Claude Fable 5
LiveBench research86.9%61.6%Claude Fable 5
LiveBench browser92.0%48.0%Claude Fable 5
LiveBench long agentic53.2%44.6%Claude Fable 5
SREBench (Vals AI)Not measured3.8%Only GPT-5.5 measured
Finance Agent (Vals AI)56.3%51.8%Claude Fable 5
Tax Agent Bench (Vals AI)38.3%21.8%Claude Fable 5
Legal Research Bench (Vals AI)49.5%40.4%Claude Fable 5
Excel Modeling Benchmark (Vals AI)73.7%64.5%Claude Fable 5
Terminal-Bench-Science (Vals AI)15.7%Not measuredOnly Claude Fable 5 measured
Time Horizon Index (Vals AI)Not measured8.3%Only GPT-5.5 measured
τ²-Bench Telecom98.5%93.9%Claude Fable 5
APEX-Agents63.6%55.1%Claude Fable 5
Remote Labor Index16.1%6.3%Claude Fable 5
OSWorld 2.0Not measured13.0%Only GPT-5.5 measured
DeepResearch BenchNot measured54.0%Only GPT-5.5 measured
PostTrainBench41.8%27.2%Claude Fable 5
Vending-Bench 2$5,680$7,524GPT-5.5
LMArena Search1229Not measuredOnly 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 index124
Reasoning benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
GPQA Diamond93.2%93.2%Tie
LiveBench reasoning89.7%89.7%Tie
MMMU Pro (Vals AI)89.3%88.3%Claude Fable 5
GPQA Diamond (Artificial Analysis run)92.6%93.5%GPT-5.5
Humanity's Last Exam (Artificial Analysis run)55.5%45.8%Claude Fable 5
GPQA Diamond (Epoch AI run)85.9%90.7%GPT-5.5
ARC-AGI98.5%95.0%Claude Fable 5
ARC-AGI-289.2%85.0%Claude Fable 5
SimpleBench81.9%69.0%Claude Fable 5
Chess puzzles47.0%63.0%GPT-5.5
Mystery game puzzles52.0%56.0%GPT-5.5
EBR-bench39.5%34.3%Claude Fable 5
LMArena Text: hard prompts15071489Claude Fable 5
LMArena Text: expert15341507Claude Fable 5
LMArena Text: hard prompts in English15091483Claude Fable 5
LMArena Vision: diagrams13571325Claude Fable 5
LMArena Vision: homework13611332Claude Fable 5
Kagi LLM Benchmark91.4%88.8%Claude Fable 5
Neither model has a result on the other 4 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index60
Math benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
OTIS Mock AIME100.0%84.4%Claude Fable 5
FrontierMath, tiers 1 to 387.0%85.3%Claude Fable 5
FrontierMath, tier 490.2%72.5%Claude Fable 5
ProofBench95.0%50.0%Claude Fable 5
LMArena Text: math15161487Claude Fable 5
LMArena Text: mathematical work15151496Claude Fable 5
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index110
Knowledge benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
MMLU Pro91.5%88.1%Claude Fable 5
LegalBench (Vals AI)88.6%86.5%Claude Fable 5
CaseLaw (Vals AI)Not measured66.2%Only GPT-5.5 measured
CorpFin (Vals AI)71.8%68.4%Claude Fable 5
TaxEval (Vals AI)76.9%75.0%Claude Fable 5
MortgageTax (Vals AI)68.9%68.8%Claude Fable 5
MedCode (Vals AI)56.1%49.1%Claude Fable 5
SimpleQA Verified70.7%63.0%Claude Fable 5
LMArena Text: science15061485Claude Fable 5
LMArena Text: medicine and healthcare14801465Claude Fable 5
LMArena Text: legal and government14981491Claude Fable 5
LMArena Text: business and finance14801478Claude Fable 5
FACTS Benchmark SuiteNot measured66.7%Only GPT-5.5 measured
Neither model has a result on the other 5 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index90
Web design benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
Design Arena: websites12951256Claude Fable 5
Design Arena: UI components13161257Claude Fable 5
Design Arena: game dev13351293Claude Fable 5
Design Arena: data viz13041264Claude Fable 5
Design Arena: 3D13181197Claude Fable 5
Design Arena: all code categories13101260Claude Fable 5
Design Arena: SVG13021234Claude Fable 5
Design Arena: ASCII art13291255Claude Fable 5
LiveBench design84.7%70.3%Claude Fable 5
GeneralLike-for-likePublic boards, shown as published, kept out of the index314
General benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
LiveBench data analysis80.5%81.6%GPT-5.5
Public Benefits Bench (Vals AI)70.4%60.9%Claude Fable 5
SAGE (Vals AI)51.9%51.5%Claude Fable 5
MedScribe (Vals AI)88.5%86.9%Claude Fable 5
Vals Multimodal Index74.2%68.1%Claude Fable 5
IFBench63.5%75.9%GPT-5.5
Long context reasoning (AA-LCR)82.3%84.3%GPT-5.5
DTBench98.4%96.0%Claude Fable 5
LMCA61.2%54.3%Claude Fable 5
Surface Evolver Bench95.0%88.1%Claude Fable 5
Furniture assembly35.8%44.2%GPT-5.5
ExploitBenchNot measured47.4%Only GPT-5.5 measured
CL-bench LifeNot measured22.2%Only GPT-5.5 measured
LMArena Text14911471Claude Fable 5
LMArena Text: instruction following15021478Claude Fable 5
LMArena Text: creative writing14941455Claude Fable 5
LMArena Vision13251297Claude Fable 5
LMArena Text: English14981470Claude Fable 5
LMArena Text: non-English14821467Claude Fable 5
LMArena Text: Chinese15431534Claude Fable 5
LMArena Text: German14861480Claude Fable 5
LMArena Text: Japanese15041499Claude Fable 5
LMArena Text: Korean14871460Claude Fable 5
LMArena Text: French15051485Claude Fable 5
LMArena Text: Spanish14981468Claude Fable 5
LMArena Text: Russian15031473Claude Fable 5
LMArena Text: Polish14941465Claude Fable 5
LMArena Text: multi-turn15041476Claude Fable 5
LMArena Text: longer queries15101484Claude Fable 5
LMArena Text: writing and language15011466Claude Fable 5
LMArena Text: entertainment and media14821449Claude Fable 5
LMArena Vision: English13231292Claude Fable 5
LMArena Vision: Chinese13731360Claude Fable 5
LMArena Vision: reading text13371306Claude Fable 5
LMArena Vision: humor13411293Claude Fable 5
LMArena Vision: recognizing thingsNot measured1231Only GPT-5.5 measured
LMArena Vision: creative writing13381301Claude Fable 5
LMArena Document14961486Claude Fable 5
Neither model has a result on the other 8 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Claude Fable 5 and GPT-5.5
BenchmarkClaude Fable 5GPT-5.5Leader
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$0.035Fits in one request
GPT-5.5$0.020Fits in one request

GPT-5.5 costs less

Repository review

50K input + 3K output tokens

Claude Fable 5$0.650Fits in one request
GPT-5.5$0.340Fits in one request

GPT-5.5 costs less

Agent loop

200K input + 10K output tokens

Claude Fable 5$2.50Fits in one request
GPT-5.5$1.30Fits in one request

GPT-5.5 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.

Specifications of Claude Fable 5 and GPT-5.5
SpecificationAnthropic Claude Fable 5OpenAI GPT-5.5
MakerAnthropicOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedJune 9, 2026April 24, 2026
Context window1M1.05M
Input $/Mtok$10.00$5.00
Output $/Mtok$50.00$30.00
Coding index79.371.3
Independent measurements behind it65
Cost per solved task$2.16$1.65
SourceOpenRouter listingOpenRouter listing

Questions

Is Claude Fable 5 better than GPT-5.5 for coding?

Pick Claude Fable 5 for coding: it scores 79.3 on the Vibe Coding Index against 71.3 for GPT-5.5. Pick GPT-5.5 for output tokens 1.7x cheaper ($30.00 vs $50.00 per million) and a lower cost per solved task ($1.65 against $2.16).

Which is cheaper, Claude Fable 5 or GPT-5.5?

Claude Fable 5 costs $10.00 per million input tokens and $50.00 per million output tokens; GPT-5.5 costs $5.00 and $30.00. Per solved SWE-bench Verified task, Claude Fable 5 costs $2.16 and GPT-5.5 $1.65.

Which has the bigger context window, Claude Fable 5 or GPT-5.5?

GPT-5.5, with 1.05M tokens against 1M.

How many benchmarks is the Claude Fable 5 vs GPT-5.5 comparison based on?

123 benchmarks have a result for both models as of October 22, 2026. Claude Fable 5's coding index rests on 6 independent benchmarks and GPT-5.5's on 5. Where only one model has a result, the page says so instead of naming a winner.

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