Removing ChatGPT custom instructions may actually improve performance

A ChatGPT Business subscriber found that removing custom instructions made Codex perform smarter and use fewer tokens, suggesting that generic custom instructions can actually degrade model performance.

2026-10-02 ~ 2026-10-02 · 2 related posts

• User finds ChatGPT Codex smarter and cheaper after removing custom instructions — doctor_dadbod · 2026-10-02
• ChatGPT Business user finds the seat without custom instructions works far better — BraveBrush8890 · 2026-10-02