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Claude Sonnet 4.5 vs Grok‑1

Anthropic Claude Sonnet 4.5 vs xAI Grok‑1 — side-by-side specs.

Anthropic
Claude Sonnet 4.5
xAI
Grok‑1
Overview
CompanyAnthropicxAI
Release dateSep 29 2025Nov 3 2023
Model type
Open sourceNoYes
Specifications
Parameters
Context window
Benchmarks
Coding
SWE-Bench Verified
77.2%
Science
GPQA Diamond
83.4%
Multimodal
MMMU
68%
Timeline
Release gapGrok‑1 shipped 696 days before Claude Sonnet 4.5

Which is better: Claude Sonnet 4.5 or Grok‑1?

Claude Sonnet 4.5 and Grok‑1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok‑1 shipped 696 days before Claude Sonnet 4.5, so benchmark comparisons should account for the intervening progress.

Grok‑1 is an open-source / open-weight model; Claude Sonnet 4.5 is proprietary.

Direct benchmark comparisons are unavailable — Claude Sonnet 4.5 and Grok‑1 don't publish scores on any of the same benchmarks.

Frequently asked questions

When was Claude Sonnet 4.5 released?
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
When was Grok‑1 released?
Grok‑1 was released by xAI on Nov 3 2023.
Is Claude Sonnet 4.5 or Grok‑1 open source?
Grok‑1 is an open-source / open-weight model released by xAI. Claude Sonnet 4.5 is a proprietary model released by Anthropic.

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