Claude Mythos vs Claude Sonnet 4.6: Frontier Preview vs Production Default

Claude MythosClaude Sonnet 4.6
arenaElo14781358
humanEval98.789
sweBench93.960
mmlu94.288.7
gpqa94.659.4
aime97.680
Price in/out ($/M)$25 / $125$3 / $15

Our verdict

Different jobs entirely: Sonnet 4.6 is the production default (generally available, $3 / $15 per M tokens, sub-second latency for chat UX). Mythos is a frontier research preview behind Project Glasswing at $25 / $125, mostly used for autonomous cybersecurity work and graduate-level reasoning. Almost no team should choose Mythos when Sonnet 4.6 will do the job; almost no team should choose Sonnet when the task actually needs Mythos.

Claude Mythos · Claude Sonnet 4.6 · All AI model comparisons