Model comparison

GPT-6 Astra vs o3

GPT-6 Astra is the stronger model overall, scoring 70.3 to 47.4 on the Noometry Index. o3 costs 5.7× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

Last verified . 31 shared benchmarks.

GPT-6 Astra OpenAI

70.3

Rank #1 Confirmed

o3 OpenAI

47.4

Rank #53 Confirmed

Summary

  • They share 31 benchmarks with published results for both. GPT-6 Astra scores higher in 9 categories and o3 in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-6 Astra leads 85.1 to 32.1.
  • The biggest single-benchmark swing is ARC-AGI-2: 95% for GPT-6 Astra and 6.5% for o3.
  • o3 is cheaper at $2 / $8 per million input/output tokens, against $10 / $50 for GPT-6 Astra.
  • GPT-6 Astra accepts more context: 1.05M tokens versus 200K.

Side by side

GPT-6 Astra and o3 specifications
GPT-6 Astrao3
ProviderOpenAIOpenAI
Noometry Index70.347.4
Released2026-09-032025-04-16
WeightsProprietaryProprietary
Context window1.05M200K
Max output128K100K
Input $ / M tokens$10$2
Output $ / M tokens$50$8
Results tracked5163

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Category by category

Coding GPT-6 Astra leads

GPT-6 Astra: 70.5 (#3), o3: 47.3 (#57)

Coding benchmarks
BenchmarkGPT-6 Astrao3
WeirdML93.6%52.4%
LMArena Coding14881408
ALE-Bench2,951933.55
SWE-bench Verified—62.3%
DeepSWE74.1%—
FrontierCode53.3%—
SWE-bench Verified (bash only)—58.4%
Aider Polyglot—81.3%
LMArena WebDev1792—
FrontierSWE65.5%—
SciCode56.5%—
GSO—8.8%
MirrorCode46.7%—
CadEval—74%

Agentic & Tool Use GPT-6 Astra leads

GPT-6 Astra: 52.3 (#3), o3: 34.3 (#42)

Agentic & Tool Use benchmarks
BenchmarkGPT-6 Astrao3
APEX-Agents64.7%—
Berkeley Function Calling Leaderboard—63%
GDPval—30.8%
Remote Labor Index20.8%—
DeepResearch Bench—45.2%
OSWorld—23%
BALROG68.3%—
LMArena Search—1144
METR Time Horizons—65.4%
Vending-Bench 215,515—

Reasoning GPT-6 Astra leads

GPT-6 Astra: 85.1 (#1), o3: 32.1 (#66)

Reasoning benchmarks
BenchmarkGPT-6 Astrao3
ARC-AGI-295%6.5%
ARC-AGI-198.5%60.8%
CritPt31.7%1.4%
Chess Puzzles72%38%
LMArena Hard Prompts14641402
Mystery Game Puzzles84%29%
DTBench97.3%84.8%
LMCA64.4%39.7%
Epoch Capabilities Index166.6146.88
SimpleBench—53.1%
Kagi LLM Benchmark—67.6%
NYT Connections (extended)98.1%—
EnigmaEval—13.1%
EBR-Bench76.2%—
Bench to the Future 30.14—
ForecastBench—62.5

Math GPT-6 Astra leads

GPT-6 Astra: 93.4 (#1), o3: 48.9 (#49)

Knowledge GPT-6 Astra leads

GPT-6 Astra: 75.3 (#1), o3: 54.5 (#47)

Knowledge benchmarks
BenchmarkGPT-6 Astrao3
GPQA Diamond95.8%81.8%
Humanity's Last Exam54.8%20.3%
SimpleQA Verified75.6%49.4%
LMArena Expert14861403
MMLU-Pro—85.9%
Confabulations—14.4%
Vectara Hallucination Rate8.7%—
GPQA (HELM)—75.3%

Multimodal GPT-6 Astra leads

GPT-6 Astra: 55.1 (#3), o3: 40.7 (#35)

Multimodal benchmarks
BenchmarkGPT-6 Astrao3
LMArena Vision12801214
GeoBench—74%
VPCT—52%
Blueprint-Bench 249.7%—
Furniture Assembly80%—
LMArena Document1468—

Multilingual GPT-6 Astra leads

GPT-6 Astra: 54.0 (#53), o3: 51.9 (#99)

Multilingual benchmarks
BenchmarkGPT-6 Astrao3
LMArena Non-English14311402
LMArena Chinese14951438
LMArena French14671430
LMArena Russian14341407
LMArena Spanish14121395
LMArena German—1420
LMArena Japanese—1404
LMArena Korean—1371

Instruction Following GPT-6 Astra leads

GPT-6 Astra: 76.6 (#37), o3: 73.0 (#122)

Instruction Following benchmarks
BenchmarkGPT-6 Astrao3
LMArena Instruction Following14541368
IFEval—86.9%

Long Context o3 leads

GPT-6 Astra: 44.7 (#57), o3: 53.2 (#6)

Long Context benchmarks
BenchmarkGPT-6 Astrao3
LMArena Longer Query14601372
Fiction.LiveBench—88.9%
CL-bench—17.8%

Writing & Preference GPT-6 Astra leads

GPT-6 Astra: 75.7 (#7), o3: 63.7 (#62)

Writing & Preference benchmarks
BenchmarkGPT-6 Astrao3
LMArena Text14431410
LMArena Creative Writing14231359
EQ-Bench Creative Writing21731676
LMArena Multi-Turn14571405
Short-Story Creative Writing—83.9%
WildBench—86.1%

Frequently asked questions

Is GPT-6 Astra better than o3?

GPT-6 Astra is the stronger model overall, scoring 70.3 to 47.4 on the Noometry Index. o3 costs 5.7× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

Which is cheaper, GPT-6 Astra or o3?

o3 is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; GPT-6 Astra lists at $10 and $50.

Is GPT-6 Astra or o3 better for coding?

GPT-6 Astra scores higher on coding benchmarks: 70.5 versus 47.3 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Astra does, with 1.05M tokens against 200K.

How many benchmarks do GPT-6 Astra and o3 share?

31 benchmarks have published results for both models. GPT-6 Astra has 51 scored results on Noometry and o3 has 63.

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