Compare / Gemini 3.8 Flash vs GPT-5.6 Luna

Gemini 3.8 Flash vs GPT-5.6 Luna

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

Gemini 3.8 Flash
Google · profile
GPT-5.6 Luna
OpenAI · profile
Results compared
26
Shared sources
6
BenchmarkMetricGemini 3.8 FlashGPT-5.6 Luna
Arena (formerly LMArena)reportedConfirmed task successIPS effect estimate 0.09-0.05
Arena (formerly LMArena)reportedPraise over complaintIPS effect estimate 0.05-0.04
Arena (formerly LMArena)reportedSteerabilityIPS effect estimate 0.040.02
Arena (formerly LMArena)reportedTool groundingIPS effect estimate 0.000.00
Arena (formerly LMArena)reportedOverallArena rating 1,4771,461
Arena (formerly LMArena)reportedBusiness, management and financeArena rating 1,4821,463
Arena (formerly LMArena)reportedCreative writingArena rating 1,4821,412
Arena (formerly LMArena)reportedExpert promptsArena rating 1,5291,491
Arena (formerly LMArena)reportedInstruction followingArena rating 1,4881,446
Arena (formerly LMArena)reportedOverallArena rating 1,4921,454
Arena (formerly LMArena)reportedWriting, literature and languageArena rating 1,4861,435
Artificial AnalysisreportedArtificial Analysis Coding Indexindex score 76.371.4
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 40.937.3
Artificial AnalysisreportedGPQA Diamond% of questions 95.3%91.1%
Artificial AnalysisreportedHumanity's Last Exam% of questions 47.8%39.5%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 84.0%83.7%
Artificial AnalysisreportedSciCode% of problems 56.6%53.6%
Artificial AnalysisreportedTerminal-Bench 2.1% of tasks 87.6%80.9%
Artificial AnalysisreportedTerminal-Bench 4.0% of tasks 19.7%11.6%
Artificial AnalysisreportedΤ-bench banking% of tasks 45.8%31.1%
GDP.pdfreportedProfessional document tasks% of rubric 23.4%22.7%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 69.7%41.0%
UGI LeaderboardreportedRequested-length error% off the requested word count 13.0%15.0%
UGI LeaderboardreportedStyle adherencescore from 0 to 1 0.340.38
UGI LeaderboardreportedWriting scorescore out of 100 78.553.7
Vending-Bench 2reportedMoney after a yearUS dollars $5,093.79$4,094.71

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.