GPT-5.6 Luna vs gpt-oss-20b: Release Comparison

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

Comparison of the GPT-5.6 Luna and gpt-oss-20b releases: 6 and 2 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 8 models.

For intelligence, GPT-5.6 Luna scores highest: GPT-5.6 Luna (max) at 38, against gpt-oss-20b (low) at 10 for gpt-oss-20b.
For output speed, gpt-oss-20b is fastest: gpt-oss-20b (low) at 264 t/s, against GPT-5.6 Luna (xhigh) at 118 t/s for GPT-5.6 Luna.
For cost per task, GPT-5.6 Luna and gpt-oss-20b tie at $0.01 (GPT-5.6 Luna (low) and gpt-oss-20b (high)).

Releases compared

Intelligence

Artificial Analysis Intelligence Index

Artificial Analysis Intelligence Index v4.3 incorporates 10 evaluations: AA-Briefcase, GDPval-AA v2, AutomationBench-AA, Terminal-Bench 4.0, SciCode, Humanity's Last Exam, GDP.pdf, CritPt, AA-Omniscience, AA-LCR v1.1

Estimate (independent evaluation forthcoming)

Artificial Analysis Intelligence Index v4.3 includes: AA-Briefcase, GDPval-AA v2, 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

GPT-5.6 Luna

Pareto line

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

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 (e.g. OpenAI for o1) or the median across providers where a first-party API is not available (e.g. Meta's Llama models).

Capability Scores

Capability Indices

Measures the performance of models on specific capabilities and industries

Finance & Accounting Index

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

Strategy & Ops Index

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

Legal Index

Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, 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, AA-Briefcase, 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, AA-Briefcase, Terminal-Bench 4.0 · Higher is better

Economics Index

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

Further details


																												Input modality	Output modality	Weights			Provider Benchmarks
GPT-5.6 Luna (max)	OpenAI	38	-	-	-	-	36	43	$0.18	$0.2	$0.20	$1.20	$0.02	$320	41k	28k	154M	117	128.28s	128.28s	132.56s	357.57s	-	1M	Jul 2026	-	Yes	Supports: text and image	Supports: text	Not available	-		View
GPT-5.6 Luna (xhigh)	OpenAI	35	38	41	35	33	34	41	$0.09	$0.2	$0.20	$1.20	$0.02	$179	24k	15k	85M	118	45.03s	45.03s	49.28s	200.27s	-	1M	Jul 2026	-	Yes	Supports: text and image	Supports: text	Not available	-		View
GPT-5.6 Luna (high)	OpenAI	32	35	37	33	30	32	38	$0.04	$0.2	$0.20	$1.20	$0.02	$108	14k	7k	50M	109	8.87s	8.87s	13.43s	133.23s	-	1M	Jul 2026	-	Yes	Supports: text and image	Supports: text	Not available	-		View
GPT-5.6 Luna (medium)	OpenAI	25	27	29	28	25	27	32	$0.02	$0.2	$0.20	$1.20	$0.02	$44	4k	2k	18M	112	2.46s	2.46s	6.91s	39.50s	-	1M	Jul 2026	-	Yes	Supports: text and image	Supports: text	Not available	-		View
GPT-5.6 Luna (low)	OpenAI	22	24	23	25	21	23	29	$0.01	$0.2	$0.20	$1.20	$0.02	$27	3k	559	10M	98	2.27s	2.27s	7.35s	24.92s	-	1M	Jul 2026	-	Yes	Supports: text and image	Supports: text	Not available	-		View
GPT-5.6 Luna (Non-reasoning)	OpenAI	16	17	15	18	-	19	22	$0.01	$0.2	$0.20	$1.20	$0.02	$23	2k	0	5M	109	0.85s	0.85s	5.44s	18.57s	-	1M	Jul 2026	-	No	Supports: text and image	Supports: text	Not available	-		View
gpt-oss-20b (low)	OpenAI	10	-	-	-	-	-	-	-	$0.1	$0.07	$0.20	-	-	-	-	-	264	0.85s	8.41s	10.30s	-	21B 3.6B active at inference time	131k	Aug 2025	May 2025	Yes	Supports: text	Supports: text	🤗	Apache 2.0	+5	View
gpt-oss-20b (high)	OpenAI	9	7	5	7	7	12	11	$0.01	$0.1	$0.06	$0.19	-	$29	18k	16k	70M	219	0.76s	9.88s	12.16s	77.75s	21B 3.6B active at inference time	131k	Aug 2025	May 2024	Yes	Supports: text	Supports: text	🤗	Apache 2.0	+6	View

GPT-5.6 Luna vs gpt-oss-20b: Release Comparison

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 Indices

Further details