Codex CLI vs GPT-5.5: Terminal Agent for SaaS Delivery vs Runtime Multimodal Model

Codex CLIGPT-5.5
arenaElo14081432
humanEval95.594.2
sweBench7066
mmlu88.693
gpqa60.868.7
aime8692
Price in/out ($/M)$9 / $36$12 / $48

Our verdict

Use Codex CLI to write the SaaS (backend, billing, auth, tests). Use GPT-5.5 inside the SaaS to power voice, vision and tool-calling features your B2B clients actually charge for. Most Alher Tech enterprise deliveries run this exact split.

Codex CLI · GPT-5.5 · All AI model comparisons