Microsoft MAI-Thinking-1 vs Codex (OpenAI)

Codex (OpenAI) edges out Microsoft MAI-Thinking-1 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 MAI-Thinking-1 requires a paid plan from day one (Not disclosed+). If you're testing the waters or running an occasional workload, that gap matters more than the score differential. Microsoft MAI-Thinking-1 starts at Not disclosed; Codex (OpenAI) starts at $0. Compare what each entry tier actually unlocks before you compare list prices -- the limits matter more than the headline number.

By use case: pick Microsoft MAI-Thinking-1 when azure / microsoft foundry shops that want a first-party reasoning model without an openai dependency, and developers who want a cost-efficient reasoning tier (sparse moe, 256k context) accessible today through openrouter, fireworks, or baseten. Pick Codex (OpenAI) when developers already paying for chatgpt plus who want a coding agent at no extra cost. 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 MAI-Thinking-1's lane, the score gap matters less than the fit.

Bottom line: Codex (OpenAI) is the safer default for most readers, but Microsoft MAI-Thinking-1 is competitive enough that the tie-breaker is your specific workload, not the spec sheet.