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 (Max, Default Fallback) at 53 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 67 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 $0.55, against Claude Fable 5.1 (Low, Default Fallback) at $2.37 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 (max with fallback)	Claude Fable 5.1 (xhigh 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	56	54	53	53	51	51	49	47	42
Finance & Accounting	61	58	56	56	56	54	54	51	49	46
Strategy & Ops	64	62	59	60	58	57	56	54	51	48
Legal	63	61	59	60	61	57	58	57	53	52
Healthcare & Medical	61	--	--	58	--	--	--	--	--	--
Engineering	60	59	56	56	57	54	54	51	49	45
Economics	66	63	61	63	62	60	60	58	55	53
AA-Briefcase v1.1	1807	1766	1690	1675	1656	1627	1581	1528	1482	1279
GDPval-AA v2.1	1866	1836	1705	1756	1733	1584	1633	1545	1468	1234
AutomationBench-AA	69.5%	65.0%	63.2%	59.4%	57.8%	61.2%	55.3%	54.7%	52.2%	52.9%
Terminal-Bench 4.0	59.6%	59.6%	56.6%	52.0%	55.1%	52.5%	52.0%	44.9%	40.4%	31.3%
SciCode	66.9%	65.0%	60.4%	63.1%	60.9%	59.3%	58.7%	56.4%	56.7%	58.6%
Humanity's Last Exam	61.4%	57.5%	55.6%	59.1%	58.7%	54.7%	55.9%	53.8%	48.9%	48.3%
GDP.pdf	26.2%	26.6%	28.8%	26.2%	26.2%	25.6%	26.8%	26.8%	28.0%	25.6%
CritPt	31.7%	31.7%	30.9%	29.7%	31.1%	27.7%	30.3%	29.1%	27.7%	17.7%
AA-Omniscience	46	43	41	43	42	40	41	38	34	39
AA-LCR v1.1	84.7%	84.7%	82.7%	85.3%	83.0%	84.3%	83.7%	84.7%	82.3%	80.7%

Cost per TaskUSD	$5.98	$3.46	$1.82	$7.63	$5.98	$1.34	$3.91	$2.98	$2.37	$0.55
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	81	82	67	62	79	52	54	56	80
Time to First Tokens	716.75	159.41	52.59	246.61	113.74	25.47	17.98	12.09	2.04	12.35
Time to First Answer Tokens	716.75	159.41	52.59	246.61	113.74	25.47	17.98	12.09	2.04	12.35
End-to-End Response Times	721.98	165.54	58.67	254.06	121.85	31.82	27.56	21.32	11.02	18.60
Time per Tasks	783.72	496.52	276.27	716.23	606.57	202.93	431.69	311.23	238.60	80.85

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

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

Intelligence

Artificial Analysis Intelligence Index

Artificial Analysis Intelligence Index v4.3.2 incorporates 10 evaluations: AA-Briefcase v1.1, GDPval-AA v2.1, AutomationBench-AA, Terminal-Bench 4.0, SciCode, Humanity's Last Exam, GDP.pdf, CritPt, AA-Omniscience, AA-LCR v1.1

No publicly available API

Artificial Analysis Intelligence Index v4.3.2 includes: AA-Briefcase v1.1, GDPval-AA v2.1, AutomationBench-AA, Terminal-Bench 4.0, SciCode, Humanity's Last Exam, GDP.pdf, CritPt, AA-Omniscience, AA-LCR v1.1. See Intelligence Index methodology for further details, including a breakdown of each evaluation and how we run them.

Intelligence Index vs. Cost per Intelligence Index 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

GDPval-AA v2.1

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 Artificial Analysis 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

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 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better

Strategy & Ops Index

Incorporates 6 evaluations: GDPval-AA v2.1, AA-Briefcase v1.1, AA-Omniscience, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better

Legal Index

Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better

Healthcare & Medical Index

Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better

Engineering Index

Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2.1, AA-Briefcase v1.1, Terminal-Bench 4.0 · Higher is better

Economics Index

Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2.1, AA-Briefcase v1.1, AA-LCR v1.1 · Higher is better

Claude Opus 5.5 vs Claude Fable 5.1: Release Comparison

Intelligence

Speed

Cost per Task

Intelligence

Artificial Analysis Intelligence Index

Artificial Analysis Intelligence Index

Intelligence Index vs. Cost per Intelligence Index 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