Compare / Claude Opus 5.5 vs Grok 4.6

Claude Opus 5.5 vs Grok 4.6

21 results from 6 sources that measured both models. Each row is in the source's own units; there is no overall winner.

Claude Opus 5.5
Anthropic · profile
Grok 4.6
xAI · profile
Results compared
21
Shared sources
6
BenchmarkMetricClaude Opus 5.5Grok 4.6
APEX-AgentsreportedTasks passed% of tasks 73.5%65.3%
Arena (formerly LMArena)reportedConfirmed task successIPS effect estimate 0.16-0.03
Arena (formerly LMArena)reportedPraise over complaintIPS effect estimate 0.19-0.00
Arena (formerly LMArena)reportedSteerabilityIPS effect estimate 0.140.03
Arena (formerly LMArena)reportedTool groundingIPS effect estimate 0.000.00
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4991,447
Arena (formerly LMArena)reportedCreative writingArena rating 1,5211,445
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5561,490
Arena (formerly LMArena)reportedInstruction followingArena rating 1,5161,451
Arena (formerly LMArena)reportedOverallArena rating 1,5091,453
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,5201,446
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 57.644.3
Artificial AnalysisreportedHumanity's Last Exam% of questions 61.4%44.1%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 84.7%81.0%
Artificial AnalysisreportedSciCode% of problems 66.9%56.5%
Artificial AnalysisreportedTerminal-Bench 4.0% of tasks 59.6%21.2%
GDP.pdfreportedProfessional document tasks% of rubric 30.6%17.2%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 72.2%49.3%
UGI LeaderboardreportedRequested-length error% off the requested word count 2.0%25.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.430.36
UGI LeaderboardreportedWriting scorescore out of 100 70.063.3

Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.