Compare / Claude Opus 4.8 vs Claude Sonnet 5.5

Claude Opus 4.8 vs Claude Sonnet 5.5

7 results from 3 sources that measured both models. Each row is in the source's own units; there is no overall winner.

Claude Opus 4.8
Anthropic · profile
Claude Sonnet 5.5
Anthropic · profile
Results compared
7
Shared sources
3
BenchmarkMetricClaude Opus 4.8Claude Sonnet 5.5
APEX-AgentsreportedTasks passed% of tasks 48.9%75.5%
Artificial AnalysisreportedArtificial Analysis Intelligence Indexindex score 41.856.0
Artificial AnalysisreportedHumanity's Last Exam% of questions 48.7%55.0%
Artificial AnalysisreportedLong-context reasoning (AA-LCR)% of questions 77.7%82.7%
Artificial AnalysisreportedSciCode% of problems 54.4%61.0%
Artificial AnalysisreportedTerminal-Bench 4.0% of tasks 21.7%63.6%
SimpleQA Verified (Epoch AI)reportedCorrect answers% of questions 53.0%46.5%

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.