Gemini 3.8 Flash 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 Gemini 3.8 Flash and Claude Fable 5.1 releases: 3 and 5 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 8 models.

For intelligence, Claude Fable 5.1 scores highest: Claude Fable 5.1 (Xhigh, Default Fallback) at 50, against Gemini 3.8 Flash (High) at 31 for Gemini 3.8 Flash.
For output speed, Gemini 3.8 Flash is fastest: Gemini 3.8 Flash (High) at 131 t/s, against Claude Fable 5.1 (Max, Default Fallback) at 69 t/s for Claude Fable 5.1.
For cost per task, Claude Fable 5.1 is cheapest: Claude Fable 5.1 (Low, Default Fallback) at $4.47, against Gemini 3.8 Flash (Medium) at $6.26 for Gemini 3.8 Flash.

Model Playground

Releases compared


	Claude Fable 5.1 (xhigh with fallback)	Claude Fable 5.1 (max with fallback)	Claude Fable 5.1 (high with fallback)	Claude Fable 5.1 (medium with fallback)	Claude Fable 5.1 (low with fallback)	Gemini 3.8 Flash (high)	Gemini 3.8 Flash (medium)	Gemini 3.8 Flash (low)
Intelligence Index	50	49	47	43	38	31	30	22
Finance & Accounting	54	54	50	47	48	42	42	34
Strategy & Ops	56	58	54	52	51	47	47	35
Legal	54	54	50	48	47	42	42	33
Healthcare & Medical	51	51	48	45	44	38	38	31
Engineering	57	57	54	50	45	38	37	31
Economics	58	59	54	51	49	41	40	34
AA-Briefcase v1.1	1651	1670	1577	1525	1479	1203	1183	1062
AutomationBench-AA	57.8%	59.4%	55.3%	54.7%	52.2%	59.9%	60.9%	36.5%
Terminal-Bench 4.0	55.1%	52.0%	52.0%	44.9%	40.4%	19.7%	19.7%	10.1%
FrontierCode 2.0	35.7%	31.6%	30.3%	28.8%	22.8%	18.7%	16.5%	8.1%
AA-Omniscience v1.1	44	46	40	36	34	23	24	13
GDP.pdf	26.2%	26.2%	26.8%	26.8%	28.0%	21.0%	22.8%	18.6%
HLE-Diamond	58.8%	60.1%	50.4%	45.0%	37.4%	33.1%	29.1%	24.3%
CritPt v2 (Hard Subset)	56.5%	51.0%	60.5%	56.5%	47.5%	43.5%	44.0%	31.5%
Terminal-Bench-Science 0.1	40.5%	43.3%	39.5%	29.0%	21.4%	10.0%	10.5%	8.1%

Cost per TaskUSD	$10.85	$12.99	$7.54	$5.56	$4.47	$7.77	$6.26	--
Input PriceUSD/1M Tokens	$10.00	$10.00	$10.00	$10.00	$10.00	$0.75	$0.75	$0.75
Output PriceUSD/1M Tokens	$50.00	$50.00	$50.00	$50.00	$50.00	$3.75	$3.75	$3.75
Cache Hit PriceUSD/1M Tokens	$0.25	$0.25	$0.25	$0.25	$0.25	$0.075	$0.075	$0.075
Cache Write PriceUSD/1M Tokens	$12.50	$12.50	$12.50	$12.50	$12.50	$0.75	$0.75	$0.75

Output SpeedTokens/s	62	69	57	56	55	131	--	--
Time to First Tokens	81.27	253.12	19.50	15.84	3.07	27.85	--	--
Time to First Answer Tokens	81.27	253.12	19.50	15.84	3.07	27.85	--	--
End-to-End Response Times	89.33	260.34	28.24	24.72	12.09	31.66	--	--
Time per Tasks	965.68	1,072.82	705.81	531.45	409.33	740.45	--	--

Context Window	1M	1M	1M	1M	1M	1M	1M	1M
Creator	Anthropic	Anthropic	Anthropic	Anthropic	Anthropic	Google	Google	Google
License	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, image, speech, and video	Supports: text, image, speech, and video	Supports: text, image, speech, and video
Output Modality	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

Gemini 3.8 Flash

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, Gemini 3.8 Flash (high) 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

Gemini 3.8 Flash (high)

Claude Fable 5.1 (max with fallback)

Natural Sounding

99%

Lexically Varied

97%

Eloquent

10%

90%

Metaphorical

78%

22%

Literate

27%

73%

Gemini 3.8 Flash 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, Gemini 3.8 Flash (high) vs Claude Fable 5.1 (max with fallback)