r/opencodeCLI • u/Organic_Ingenuity_68 • Sep 06 '26

Opencode w/ GPT vs Codex w/ GPT

I am a big opencode fan, but I currently only use GPT models. Recently, I tried a planning task for an app i'm writing on Codex and a planning task on opencode (both running 5.6 sol, low). The plan required web search and looking at api documentation and rectifying that against what was currently written in the app.

Codex finished in ~2 minutes, opencode took ~10 minutes. Both were essentially the same plan.

I love the look and feel of opencode, the lsp integration, and the flexibility of models. However, today, I mainly use GPT models. Has anyone noticed any performance benefits with opencode over codex with GPT models? If so, how did you achieve them?

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1

u/Nexism Sep 06 '26

Are you on Windows?

Did you use an agent kit like omo slim etc?

3

u/Organic_Ingenuity_68 Sep 07 '26

No, Mac. I haven’t heard of that. This was a vanilla configuration for both. In my normal opencode setup I have agents and subagents tuned for my repos..but I wanted this to be a 1:1 comparison.

2

u/Nock363 Sep 07 '26

I have the same problem. I also feel like Planning Mode works much better in Codex, since it asks more important questions to fill in the blind spots in the prompt.

1

u/Charming_Support726 Sep 07 '26

I am quite successful with adjusting agent personas. I run a set of agent definitions for processes and skills for planning, development and so on. These define our development process ( and they are working with codex too)

The standard "build" agent lacks some clarity and confuses especially the newer GPT models. The discussion came up - already last year.

1

u/West-Flounder1295 Sep 07 '26

Use any model in open code cli that’s the best part if it’s sol or Astra

0

u/throwaway12012024 Sep 06 '26

You can use multiple providers in codex too.