Model comparison

GPT-6 Astra vs Grok 4.20 (Non-Reasoning)

GPT-6 Astra is the stronger model overall, scoring 70.8 to 48.6 on the Noometry Index. Grok 4.20 (Non-Reasoning) costs 13× less per token, which makes it the better buy when GPT-6 Astra's lead doesn't matter for your workload.

Last verified . 38 shared benchmarks.

GPT-6 Astra OpenAI

70.8

Rank #1 Confirmed

Grok 4.20 (Non-Reasoning) xAI

48.6

Rank #54 Confirmed

Summary

  • They share 38 benchmarks with published results for both. GPT-6 Astra scores higher in 8 categories and Grok 4.20 (Non-Reasoning) in 2 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-6 Astra leads 93.5 to 48.2.
  • The biggest single-benchmark swing is ProofBench: 99% for GPT-6 Astra and 14% for Grok 4.20 (Non-Reasoning).
  • Grok 4.20 (Non-Reasoning) is cheaper at $1.25 / $2.50 per million input/output tokens, against $10 / $50 for GPT-6 Astra.
  • GPT-6 Astra accepts more context: 1.05M tokens versus 1M.

Side by side

GPT-6 Astra and Grok 4.20 (Non-Reasoning) specifications
GPT-6 AstraGrok 4.20 (Non-Reasoning)
ProviderOpenAIxAI
Noometry Index70.848.6
Released2026-09-032026-02-17
WeightsProprietaryProprietary
Context window1.05M1M
Max output128K30K
Input $ / M tokens$10$1.25
Output $ / M tokens$50$2.50
Results tracked5646

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Category by category

Coding GPT-6 Astra leads

GPT-6 Astra: 73.7 (#2), Grok 4.20 (Non-Reasoning): 42.1 (#112)

Coding benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena WebDev17861375
WeirdML93.6%52.3%
LMArena Coding14871459
ALE-Bench2,9511,150
DeepSWE74.1%—
FrontierCode53.3%—
FrontierSWE65.5%—
SciCode56.5%—
GSO79.4%—
MirrorCode46.7%—

Agentic & Tool Use GPT-6 Astra leads

GPT-6 Astra: 52.9 (#3), Grok 4.20 (Non-Reasoning): 34.4 (#46)

Agentic & Tool Use benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
Vending-Bench 215,5154,663
Terminal-Bench—57.3%
APEX-Agents64.7%—
Remote Labor Index20.8%—
τ²-bench Banking—18%
BALROG68.3%—
GDP.pdf34.2%—
LMArena Search—1189

Reasoning GPT-6 Astra leads

GPT-6 Astra: 85.1 (#1), Grok 4.20 (Non-Reasoning): 52.3 (#32)

Reasoning benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
ARC-AGI-295%65.1%
NYT Connections (extended)98.1%85.4%
ARC-AGI-198.5%89.5%
Chess Puzzles72%24%
LMArena Hard Prompts14621451
DTBench97.3%90.1%
LMCA64.4%38.7%
Epoch Capabilities Index166.45151.98
Kagi LLM Benchmark—75%
CritPt31.7%—
Thematic Generalization—63.8%
EBR-Bench76.2%—
Mystery Game Puzzles84%—
Bench to the Future 30.14—
ForecastBench—61.4

Math GPT-6 Astra leads

GPT-6 Astra: 93.5 (#2), Grok 4.20 (Non-Reasoning): 48.2 (#65)

Math benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
FrontierMath (Tiers 1-3)93.7%44.9%
FrontierMath Tier 497.6%17.1%
OTIS Mock AIME 2024-2025100%92.2%
ProofBench99%14%
LMArena Math14651455
FrontierMath Erdős2.9%—

Knowledge GPT-6 Astra leads

GPT-6 Astra: 75.3 (#1), Grok 4.20 (Non-Reasoning): 52.8 (#60)

Knowledge benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
GPQA Diamond95.8%89.3%
SimpleQA Verified75.6%30.2%
LMArena Expert14831439
Humanity's Last Exam54.8%—
Vectara Hallucination Rate8.7%—

Multimodal GPT-6 Astra leads

GPT-6 Astra: 55.0 (#3), Grok 4.20 (Non-Reasoning): 33.3 (#98)

Multimodal benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena Vision12811263
Blueprint-Bench 249.7%0%
LMArena Document14681416
Furniture Assembly80%—

Multilingual Too close to call

GPT-6 Astra: 53.7 (#61), Grok 4.20 (Non-Reasoning): 54.5 (#40)

Multilingual benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena Non-English14301441
LMArena Chinese14841481
LMArena French14561476
LMArena German14401465
LMArena Japanese13791449
LMArena Korean14261417
LMArena Russian14361458
LMArena Spanish14071443

Instruction Following GPT-6 Astra leads

GPT-6 Astra: 76.3 (#44), Grok 4.20 (Non-Reasoning): 74.8 (#83)

Instruction Following benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena Instruction Following14501420

Long Context Too close to call

GPT-6 Astra: 44.5 (#62), Grok 4.20 (Non-Reasoning): 45.5 (#34)

Long Context benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena Longer Query14561437
CL-bench—22.2%
CL-bench Life—11.9%

Writing & Preference GPT-6 Astra leads

GPT-6 Astra: 75.3 (#7), Grok 4.20 (Non-Reasoning): 65.7 (#44)

Writing & Preference benchmarks
BenchmarkGPT-6 AstraGrok 4.20 (Non-Reasoning)
LMArena Text14411451
LMArena Creative Writing14181438
EQ-Bench Creative Writing21731574
LMArena Multi-Turn14481456

Frequently asked questions

Is GPT-6 Astra better than Grok 4.20 (Non-Reasoning)?

GPT-6 Astra is the stronger model overall, scoring 70.8 to 48.6 on the Noometry Index. Grok 4.20 (Non-Reasoning) costs 13× 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 Grok 4.20 (Non-Reasoning)?

Grok 4.20 (Non-Reasoning) is cheaper. It lists at $1.25 per million input tokens and $2.50 per million output tokens; GPT-6 Astra lists at $10 and $50.

Is GPT-6 Astra or Grok 4.20 (Non-Reasoning) better for coding?

GPT-6 Astra scores higher on coding benchmarks: 73.7 versus 42.1 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Astra does, with 1.05M tokens against 1M.

How many benchmarks do GPT-6 Astra and Grok 4.20 (Non-Reasoning) share?

38 benchmarks have published results for both models. GPT-6 Astra has 56 scored results on Noometry and Grok 4.20 (Non-Reasoning) has 46.

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