#Codex cant handle reasoning?

1 messages · Page 1 of 1 (latest)

ember mountain
#

whenever i ask codex to do something requriing creative reasoning, it fails. codex can only handle find problem --> is solvable --> fix (or a variation) atleast from my testing. regular chatgpt imo is better at coding then codex in some cases

tacit wolfBOT
#

Hi @ember mountain. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base. :wave:

#

You’re running into a real tradeoff that OpenAI explicitly calls out: different models (and products built on them) are tuned for different things.

From the docs:

  • GPT‑5.2 (and its chat variants) is the general, broad reasoning model: “best for your most complex tasks that require broad world knowledge… complex reasoning, broad world knowledge, and code-heavy or multi-step agentic tasks.” [Meet the models]
  • GPT‑5.2‑Codex is the coding‑optimized variant, “specifically designed for use in Codex… for agentic coding tasks in Codex or Codex-like environments.” [Latest FAQ; Meet the models]

So Codex is optimized around structured coding workflows (edit, run, fix, refactor, tests, etc.), not open‑ended creative reasoning. That matches your observation that it’s very good at “find problem → is solvable → fix,” but can feel weaker on more free‑form, creative or high‑level design questions.

A few concrete implications from the docs:

  • For complex, creative, or ambiguous tasks, OpenAI recommends the general GPT‑5.x models (e.g., gpt-5.2 or gpt-5.2-pro) rather than the Codex variant. [Meet the models]
  • For agentic coding inside Codex, they recommend gpt-5.2-codex (and gpt-5.3-codex as it rolls out), which also has a reasoning_effort knob (low/medium/high/xhigh) you can turn up when the coding task itself is complex. [Latest FAQ; Codex multi-agents]
#

So your experience that “regular ChatGPT is better at coding than Codex in some cases” is plausible: if “coding” in those cases really means creative problem framing, architecture, or multi‑step reasoning, the general GPT‑5.2 chat model is exactly what OpenAI positions for that.

If you want Codex to reason more on tough coding tasks, the official guidance is to:

  • Increase reasoning_effort for the Codex model when using the API. [GPT‑5 prompting; Latest FAQ]
  • Use multi‑agent setups where a stronger‑reasoning model (e.g., gpt-5.3-codex or even a general GPT‑5.x model) handles planning/review, and faster agents handle simpler sub‑tasks. [Codex multi-agents]

But if your main need is “creative reasoning + code,” the docs suggest you’ll often be better off with the general GPT‑5.2 / GPT‑5.2‑Pro models rather than Codex.

Note: you can ask me a follow up question by @ mentioning me again :speech_balloon:

#

@ember mountain Kapa.ai is still learning and improving, please let me know how I did by reacting below.

ember mountain
#

e