0

Claude Opus 4.5 vs Grok 4.1 Fast

Head to head on 29 shared benchmarks, with price, context window, and release dates.

Benchmark scores

44

evals · sort by any column, ⤢ to expand fullscreen

Model
Claude Opus 4.5

Anthropic

62.7%61.3%1683elo73.181.0%12.1313.2%83.8%43.0%83.5%78.1%79.7%74.4%62.5%81.3%90.4%80.1%73.8%45.2%83.2%88.9%68.7%36.0%45.0%47.0%74.3%40.9%20.6%86.3%-16.7%35.6%6.1%20.7%84.7%--100.0%37.477.5%45.370.7%79.2%61.862.2%
Grok 4.1 Fast

xAI

34.3%66.0%1324elo40.163.7%11.85.1%35.0%36.5%80.2%64.7%69.6%52.2%28.2%74.3%83.7%80.2%39.9%28.1%78.7%74.3%42.6%4.0%31.3%29.6%73.1%14.4%1.2%63.7%62.0%-----60.8%100.0%-------51.0%
2 / 2 models
AttributeClaude Opus 4.5

Anthropic

Grok 4.1 Fast

xAI

DescriptionClaude Opus 4.5 is an AI model from Anthropic.Grok 4.1 Fast is an AI model from xAI.
FamilyClaudeGrok
Params--
Open weightsclosedclosed
Licenseproprietaryproprietary
Released24 Nov 202519 Nov 2025
Context200,000-
Input $/1M$5.00-
Output $/1M$25.00-
Cache read $/1M$0.500-
Cache write $/1M$6.250-
Speed0 tok/s0 tok/s
Latency0.00 s0.00 s
Modalitiesfile, image, texttext
Providers--
PublisherAnthropicxAI
Reported scores
Infraresolutionbench80.2% (150 samples)
Agent Diff Bench62.0% (179 samples)
Medpt100.0% (15 samples)
Hanabi11.8 (15 samples)
SciCode29.6% (AA)

FAQ

Is Claude Opus 4.5 or Grok 4.1 Fast better?
Across the 29 benchmarks both models report on Sophon, Claude Opus 4.5 leads on 27 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do Claude Opus 4.5 and Grok 4.1 Fast compare on GPQA Diamond?
Claude Opus 4.5 scores 81.0% and Grok 4.1 Fast scores 63.7% on GPQA Diamond.
When were Claude Opus 4.5 and Grok 4.1 Fast released?
Claude Opus 4.5 was released 24 Nov 2025 by Anthropic. Grok 4.1 Fast was released 19 Nov 2025 by xAI.

Comparing something else? Build your own side-by-side.