Claude Mythos Preview vs Claude Opus 4.8 — Who Actually Wins? Real Benchmark Data (2026)

head to head

Claude Mythos Preview vs Claude Opus 4.8

4 shared benchmarks

4

wins

0

ties

0

wins

86.9%

BrowseComp

84.3%

94.6%

GPQA Diamond

91.0%

64.7%

Humanity's Last Exam

49.8%

77.8%

SWE-bench Pro

69.2%