Codex (OpenAI) vs Microsoft Agent 365

Codex (OpenAI) edges out Microsoft Agent 365 by 0.8 points (8.3 vs 7.5) -- a A-tier vs B-tier split that's narrow but real. Not a blowout; both belong on a shortlist. The score gap shows up most clearly in the categories that matter for Codex (OpenAI)'s strengths, so if those categories are your priority, the lead translates.

On pricing, Codex (OpenAI) starts free while Microsoft Agent 365 requires a paid plan from day one ($15+). If you're testing the waters or running an occasional workload, that gap matters more than the score differential. Codex (OpenAI) starts at $0; Microsoft Agent 365 starts at $15. Compare what each entry tier actually unlocks before you compare list prices -- the limits matter more than the headline number.

By use case: pick Codex (OpenAI) when developers already paying for chatgpt plus who want a coding agent at no extra cost. Pick Microsoft Agent 365 when enterprise it and security teams running mixed-ai environments who need a single pane of glass over local agents (openclaw, copilot cli, claude code), copilot studio agents, and cloud agents in aws bedrock / google cloud / azure. The two tools aren't fighting for the same person -- they're aiming at adjacent jobs that occasionally overlap. If you're squarely in Codex (OpenAI)'s lane, the tier-list ranking and the use-case fit point the same direction; if you're in Microsoft Agent 365's lane, the score gap matters less than the fit.

Bottom line: Codex (OpenAI) is the safer default for most readers, but Microsoft Agent 365 is competitive enough that the tie-breaker is your specific workload, not the spec sheet.