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Grok 4.1 Fast vs Grok 4.5

Grok 4.1 Fast (xAI) and Grok 4.5 (xAI) compared on benchmarks, pricing, context window, and use-case rankings.

AttributeGrok 4.1 FastxAIGrok 4.5xAI · 2 in the news
Scores
Intelligence (ECI)154
Coding4191
Math5285
Reasoning & Knowledge5170
Agentic & Tools4675
Specifications
DeveloperxAIxAI
FamilyGrokGrok
ReleasedNov 19, 2025Jul 8, 2026
Parameters
AvailabilityAPI accessAPI access
Context window500K
Price — $/M input$2.00
Price — $/M output$6.00
Inputstext, image, file
Outputstext
Benchmarks
AIME 2024/202589%98%
APEX13%34%
GPQA Diamond85%93%
Humanity's Last Exam18%40%
LiveCodeBench82%
MMLU-Pro85%
SciCode44%54%
SimpleBench56%70%
WebDev Arena12231551
τ²-bench93%
ARC-AGI87%
ARC-AGI-253%
SimpleQA Verified54%
WeirdML46%

Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.

Frequently asked questions

Which is better for coding, Grok 4.1 Fast or Grok 4.5?

Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Grok 4.5 ranks higher — 91th vs 41th percentile among the models tracked on Model Beat.

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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.