Claude Mythos vs Gemini 3 Ultra: Capability vs Context

Claude MythosGemini 3 Ultra
arenaElo14781441
humanEval98.791
sweBench93.966
mmlu94.293.4
gpqa94.672.6
aime97.693
Price in/out ($/M)$25 / $125$18 / $72

Our verdict

Gemini 3 Ultra has a 3× larger context window (3M vs 1M) and native video, which Mythos does not match. Mythos returns the favor on raw capability: ~23 GPQA points and ~8 HumanEval points ahead, plus saturated cybersecurity benchmarks. For whole-movie or 2000-page workloads on Vertex AI, Ultra is the right pick. For frontier reasoning and code where your data fits in 1M tokens, Mythos, if you can get access.

Claude Mythos · Gemini 3 Ultra · All AI model comparisons