Compare / Claude Opus 5.5 vs GPT-5.4

Claude Opus 5.5 vs GPT-5.4

18 results from 5 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
GPT-5.4
OpenAI · profile
Results compared
18
Shared sources
5
BenchmarkMetricClaude Opus 5.5GPT-5.4
APEX-AgentsreportedTasks passed% of tasks 73.5%52.4%
Arena (formerly LMArena)reportedConfirmed task successIPS effect estimate 0.16-0.04
Arena (formerly LMArena)reportedPraise over complaintIPS effect estimate 0.19-0.01
Arena (formerly LMArena)reportedSteerabilityIPS effect estimate 0.140.02
Arena (formerly LMArena)reportedTool groundingIPS effect estimate 0.000.00
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4991,482
Arena (formerly LMArena)reportedCreative writingArena rating 1,5211,443
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5561,515
Arena (formerly LMArena)reportedInstruction followingArena rating 1,5161,471
Arena (formerly LMArena)reportedOverallArena rating 1,5091,475
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,5201,465
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 57.639.0
Artificial AnalysisreportedHumanity's Last Exam% of questions 61.4%43.7%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 84.7%82.0%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 72.2%45.1%
UGI LeaderboardreportedRequested-length error% off the requested word count 2.0%30.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.430.40
UGI LeaderboardreportedWriting scorescore out of 100 70.068.8

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.