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Claude 2.1 vs Grok 4.1 Fast

Anthropic Claude 2.1 vs xAI Grok 4.1 Fast — side-by-side specs.

Anthropic
Claude 2.1
xAI
Grok 4.1 Fast
Overview
CompanyAnthropicxAI
Release dateNov 21 2023Nov 19 2025
Model type
Open sourceNoNo
Specifications
Parameters
Context window
Benchmarks
Science reasoning
GPQA Diamond
Software engineering
SWE-Bench Verified
Multimodal understanding
MMMU
Timeline
Release gapClaude 2.1 shipped 729 days before Grok 4.1 Fast

Which is better: Claude 2.1 or Grok 4.1 Fast?

Claude 2.1 and Grok 4.1 Fast do not have directly comparable benchmark scores published on GPQA Diamond, SWE-Bench Verified, or MMMU. Claude 2.1 shipped 729 days before Grok 4.1 Fast, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — at least one of these models has not published scores on GPQA Diamond, SWE-Bench Verified, or MMMU.

Frequently asked questions

When was Claude 2.1 released?
Claude 2.1 was released by Anthropic on Nov 21 2023.
When was Grok 4.1 Fast released?
Grok 4.1 Fast was released by xAI on Nov 19 2025.

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