The closest alternative to GPT-5.3-Codex is MiMo-V2.5-Pro — comparable intelligence (53.8 vs 53.6); for a cheaper option, Qwen3.7 Max runs $1.25/M vs $1.75/M; for more speed, MiniMax M2.7 hits 211 t/s; and the best open-weight substitute is MiniMax M3.
MiMo-V2.5-Pro is the closest alternative to GPT-5.3-Codex, with an Intelligence Index of 53.8 (GPT-5.3-Codex scores 53.6) at $0.435 per million input tokens.
Yes — Qwen3.7 Max costs $1.25 per million input tokens versus $1.75 for GPT-5.3-Codex, while staying within ~8 points of its Intelligence Index.
MiniMax M3 is the strongest open-weight alternative to GPT-5.3-Codex — downloadable from Hugging Face and self-hostable, scoring 54.7 on intelligence.