Claude Opus 5.5 vs Claude Fable 5.1: Release Comparison

Name: Intelligence
Creator: Artificial Analysis
License: https://artificialanalysis.ai/docs/legal/Terms-of-Use.pdf

Comparison of the Claude Opus 5.5 and Claude Fable 5.1 releases: 5 and 5 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 10 models.

For intelligence, Claude Opus 5.5 scores highest: Claude Opus 5.5 (Max, Default Fallback) at 58, against Claude Fable 5.1 (Xhigh, Default Fallback) at 50 for Claude Fable 5.1.
For output speed, Claude Opus 5.5 is fastest: Claude Opus 5.5 (Max, Default Fallback) at 96 t/s, against Claude Fable 5.1 (Max, Default Fallback) at 71 t/s for Claude Fable 5.1.
For cost per task, Claude Opus 5.5 is cheapest: Claude Opus 5.5 (Low, Default Fallback) at $0.98, against Claude Fable 5.1 (Low, Default Fallback) at $4.47 for Claude Fable 5.1.

Model Playground

Releases compared


	Claude Opus 5.5 (max with fallback)	Claude Opus 5.5 (xhigh with fallback)	Claude Opus 5.5 (high with fallback)	Claude Fable 5.1 (xhigh with fallback)	Claude Fable 5.1 (max with fallback)	Claude Opus 5.5 (medium with fallback)	Claude Fable 5.1 (high with fallback)	Claude Fable 5.1 (medium with fallback)	Claude Fable 5.1 (low with fallback)	Claude Opus 5.5 (low with fallback)
Intelligence Index	58	57	52	50	49	48	47	43	38	35
Finance & Accounting	59	56	53	54	54	51	50	47	48	42
Strategy & Ops	61	59	58	56	58	56	54	52	51	48
Legal	58	55	52	54	54	50	50	48	47	43
Healthcare & Medical	58	56	52	51	51	51	48	45	44	45
Engineering	65	62	58	57	57	54	54	50	45	43
Economics	62	60	57	58	59	54	54	51	49	45
AA-Briefcase v1.1	1801	1761	1682	1651	1670	1622	1577	1525	1479	1279
AutomationBench-AA	69.5%	65.0%	63.2%	57.8%	59.4%	61.2%	55.3%	54.7%	52.2%	52.9%
Terminal-Bench 4.0	59.6%	59.6%	56.6%	55.1%	52.0%	52.5%	52.0%	44.9%	40.4%	31.3%
FrontierCode 2.0	46.4%	43.8%	35.9%	35.7%	31.6%	33.1%	30.3%	28.8%	22.8%	15.8%
AA-Omniscience v1.1	48	43	42	44	46	40	40	36	34	39
GDP.pdf	26.2%	26.6%	28.8%	26.2%	26.2%	25.6%	26.8%	26.8%	28.0%	25.6%
HLE-Diamond	67.9%	64.0%	55.6%	58.8%	60.1%	51.4%	50.4%	45.0%	37.4%	41.7%
CritPt v2 (Hard Subset)	61.0%	63.0%	58.0%	56.5%	51.0%	52.5%	60.5%	56.5%	47.5%	33.5%
Terminal-Bench-Science 0.1	59.0%	61.9%	49.0%	40.5%	43.3%	43.3%	39.5%	29.0%	21.4%	24.3%

Cost per TaskUSD	$10.04	$6.05	$3.46	$10.85	$12.99	$2.45	$7.54	$5.56	$4.47	$0.98
Input PriceUSD/1M Tokens	$4.00	$4.00	$4.00	$10.00	$10.00	$4.00	$10.00	$10.00	$10.00	$4.00
Output PriceUSD/1M Tokens	$20.00	$20.00	$20.00	$50.00	$50.00	$20.00	$50.00	$50.00	$50.00	$20.00
Cache Hit PriceUSD/1M Tokens	$0.20	$0.20	$0.20	$0.25	$0.25	$0.20	$0.25	$0.25	$0.25	$0.20
Cache Write PriceUSD/1M Tokens	$5.00	$5.00	$5.00	$12.50	$12.50	$5.00	$12.50	$12.50	$12.50	$5.00

Output SpeedTokens/s	96	83	80	63	71	80	58	58	57	79
Time to First Tokens	721.30	128.76	47.50	75.86	267.16	20.87	18.35	12.88	3.05	10.86
Time to First Answer Tokens	721.30	128.76	47.50	75.86	267.16	20.87	18.35	12.88	3.05	10.86
End-to-End Response Times	726.54	134.75	53.74	83.82	274.21	27.09	26.92	21.56	11.84	17.16
Time per Tasks	1,140.53	785.05	469.54	973.02	1,056.84	338.09	699.52	522.45	406.40	149.28

Context Window	1M	1M	1M	1M	1M	1M	1M	1M	1M	1M
Creator	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic
License	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary	Proprietary
Input Modality	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image	Supports: text and image
Output Modality	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text	Supports: text
Providers

Updated

Intelligence

Artificial Analysis Intelligence Index · Higher is better

Speed

Output tokens per second · Higher is better

Cost per Task

Weighted average cost (USD) per Intelligence Index task · Lower is better

IntelligenceUpdated

Artificial Analysis Intelligence Index

Artificial Analysis Intelligence Index v5.0 incorporates 9 evaluations: AA-Briefcase v1.1, AutomationBench-AA, Terminal-Bench 4.0, FrontierCode 2.0, AA-Omniscience v1.1, GDP.pdf, HLE-Diamond, CritPt v2 (Hard Subset), and Terminal-Bench-Science 0.1

No publicly available API

Artificial Analysis Intelligence Index v5.0 includes: AA-Briefcase v1.1, AutomationBench-AA, Terminal-Bench 4.0, FrontierCode 2.0, AA-Omniscience v1.1, GDP.pdf, HLE-Diamond, CritPt v2 (Hard Subset), Terminal-Bench-Science 0.1. See Intelligence Index methodology for further details, including a breakdown of each evaluation and how we run them.

Intelligence Index vs. Cost per Task

Artificial Analysis Intelligence Index · Weighted average cost (USD) per Artificial Analysis Intelligence Index task

Most attractive quadrant

Claude Opus 5.5

Claude Fable 5.1

Pareto line

AA-Briefcase v1.1

AutomationBench-AA

Cost per Task (USD, Log Scale)

Weighted average cost per Intelligence Index task. Each evaluation’s cost is calculated from input, cache hit, cache write, reasoning, and answer token prices, divided by task count, and weighted by its Intelligence Index weight.

Cost

Cost per Intelligence Index Task

Weighted average cost (USD) per Intelligence Index task · Segmented by token type · Lower is better

No publicly available API

Speed & Latency

Output Speed

Output tokens per second · Higher is better

No publicly available API

Tokens per second received while the model is generating tokens (ie. after first chunk has been received from the API for models which support streaming).

Figures represent performance of the model's first-party API or the median across providers where a first-party API is not available.

Capability Scores

Capability Indexes

Measures the performance of models on specific capabilities and industries

Finance & Accounting Index

Incorporates 5 evaluations: AA-Briefcase v1.1, AA-Omniscience v1.1, HLE-Diamond, AutomationBench-AA, GDP.pdf · Higher is better

Strategy & Ops Index

Incorporates 4 evaluations: AutomationBench-AA, AA-Briefcase v1.1, AA-Omniscience v1.1, GDP.pdf · Higher is better

Legal Index

Incorporates 5 evaluations: AA-Omniscience v1.1, AA-Briefcase v1.1, HLE-Diamond, GDP.pdf, AutomationBench-AA · Higher is better

Healthcare & Medical Index

Incorporates 5 evaluations: AA-Omniscience v1.1, AA-Briefcase v1.1, MLCR-AA, AutomationBench-AA, HLE-Diamond · Higher is better

Engineering Index

Incorporates 7 evaluations: AA-Omniscience v1.1, CritPt v2 (Hard Subset), Terminal-Bench-Science 0.1, HLE-Diamond, Terminal-Bench 4.0, FrontierCode 2.0, AA-Briefcase v1.1 · Higher is better

Economics Index

Incorporates 4 evaluations: AA-Briefcase v1.1, AA-Omniscience v1.1, HLE-Diamond, GDP.pdf · Higher is better

Benchmarks

AA-PersonalityBenchNew

Model AvsModel B

AA-PersonalityBench: Expressiveness Index, Claude Opus 5.5 (max with fallback) vs Claude Fable 5.1 (max with fallback)

Chance each model’s answer is judged to show more of each trait from their Elo gap · 50% is an even match

Claude Opus 5.5 (max with fallback)

Claude Fable 5.1 (max with fallback)

Eloquent

92%

Natural Sounding

10%

90%

Lexically Varied

24%

76%

Metaphorical

44%

56%

Literate

51%

49%

Claude Opus 5.5 vs Claude Fable 5.1: Release Comparison

Intelligence

Speed

Cost per Task

IntelligenceUpdated

Artificial Analysis Intelligence Index

Artificial Analysis Intelligence Index

Intelligence Index vs. Cost per Task

Cost per Intelligence Index Task

Artificial Analysis Intelligence Index

Cost

Cost per Intelligence Index Task

Cost per Intelligence Index Task

Speed & Latency

Output Speed

Output Speed

Model Performance Representation

Capability Scores

Capability Indexes

Benchmarks

AA-PersonalityBenchNew

AA-PersonalityBench: Expressiveness Index, Claude Opus 5.5 (max with fallback) vs Claude Fable 5.1 (max with fallback)