Compare / GPT-5.6 Terra vs GPT-6 Luna

GPT-5.6 Terra vs GPT-6 Luna

19 results from 5 sources that measured both models. Each row is in the source's own units; there is no overall winner.

GPT-5.6 Terra
OpenAI · profile
GPT-6 Luna
OpenAI · profile
Results compared
19
Shared sources
5
BenchmarkMetricGPT-5.6 TerraGPT-6 Luna
APEX-AgentsreportedTasks passed% of tasks 58.2%44.3%
Arena (formerly LMArena)reportedConfirmed task successIPS effect estimate -0.060.05
Arena (formerly LMArena)reportedPraise over complaintIPS effect estimate 0.03-0.03
Arena (formerly LMArena)reportedSteerabilityIPS effect estimate 0.040.02
Arena (formerly LMArena)reportedTool groundingIPS effect estimate 0.000.00
Arena (formerly LMArena)reportedOverallArena rating 1,4671,422
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4661,452
Arena (formerly LMArena)reportedCreative writingArena rating 1,4281,403
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5041,505
Arena (formerly LMArena)reportedInstruction followingArena rating 1,4621,443
Arena (formerly LMArena)reportedOverallArena rating 1,4651,442
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,4451,415
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 42.138.1
Artificial AnalysisreportedHumanity's Last Exam% of questions 42.9%38.5%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 83.0%83.3%
Artificial AnalysisreportedSciCode% of problems 55.0%54.6%
Artificial AnalysisreportedTerminal-Bench 4.0% of tasks 35.4%12.6%
GDP.pdfreportedProfessional document tasks% of rubric 24.7%23.0%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 43.2%41.4%

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.