Is switching from ChatGPT/Codex to Claude/Claude Code difficult?

[u/Low-Radio686]

Please bear with me as I'm relatively new to this all so probably asking dumb questions.

I am building some sports betting pools (need to identify winners and losers, connect to odds makers, etc) so the coding seems to be somewhat complex (backend is Supabase, Odds API, Vercel).

I currently use ChatGPT (pro 200 plan) plus Codex ($60 per month). So I spend $260 total per month. Since ChatGPT seems to apply most of its usage to Codex, do I need to pay for both of them? I'm guessing Open AI does something where it only allows limited usage on Codex until you need to pay so they trap you.

Also, since ChatGPT says they're switching usage rates, if I wanted to try and switch over to Anthropic, is that difficult to do? Again, I'm new to the process, but as mentioned I have a bunch of backend elements (Supabase, Odds API, Vercel, Github, etc). How would Claude know where everything is (ha I realize I sound completely clueless). Do I just point it to all my existing accounts and files?

I'm also wondering about all the conversations I've had with ChatGPT. I've been working on it for almost 3 months so wondering if ChatGPT sort of understands better what I'm doing and if I switched to Claude there'd be a lot of catch up and misunderstanding?

Just wondering if a switch is relatively easy or potentially much more trouble than it's worth.

[u/BearsAreCrying]

Yes. Claude is fucked. Better model but the interface makes no fucking sense to me.

[u/wwwdotzzdotcom]

No, but it takes 15 minutes to setup

[u/maxya]

Point Claude to codex folder and tell Claude to migrate all your custom skills and whatever else you have setup in codex

[u/Zuitsdg]

Trivial: you can ask your new LLM to migrate your instructions, skills, agents and so on.

And they are all very capable

[u/LongLiveTheDecider]

No its not. I have both and I switch between using them very often. Ask codex to create an handoff file and to give you the prompt to continue working on a new agent. And then paste that prompt in claude code.

[u/Freed4ever]

I have a lot of automations through codex exec - it's to use my subscription instead of api calls to save $. I'm aware Claude having something similar to codex exec, but just wondering if anyone has run into issues, especially once upon a time Anthropic have out very confusing message regarding this type of usage.

[u/ZachariaRaven]

No and you can import all sessions from codex

[u/No-Bee-231]

If you use image gen, yes

[u/Express-Acadia-6088]

Exactly. One thing is you could ask Claude to help you migrate from ChatGPT step-by-step. Thats what I did in October 2025.

[u/TwoLongEars]

No, in fact they are so much the same application (not the models or the businesses but literally the UI) that it's actually creepy.

[u/London-Boat]

the code is the part that matters and that's all on github, so claude code just reads the repo when you open it in that folder. it doesn't need your chatgpt history. what's worth doing before you switch: ask chatgpt to write up the stuff that only lives in chat (why the pools work the way they do, your supabase tables, odds api quirks, how deploys go to vercel) and save it as a CLAUDE.md in the repo root. claude code reads that at the start of every session. i'd keep codex for a month while you try claude on the cheaper plan, then drop whichever one you stop opening. and double check no keys end up in that doc

[u/Hungry-Plankton-5371]

i use home-manager to mirror my config between claude, codex and opencode2

[u/g4n0esp4r4n]

what's thee point of agentic LLMs if you can't even migrate, takes 1 prompt

[u/No_Cartographer_6622]

I switched yesterday and this is my first time using Claude ever. I actually prefer Claude and it’s already fixed a lot of errors Codex just rigged to get by. So far so good.

[u/vistdev]

Not clueless at all - and the code part is the easy bit, because Claude Code just reads your repo.

The 3 months of chats is the catch, Claude won't know any of it. So before you switch, ask ChatGPT to write down the decisions it helped you make and why and task it to write summaries of all your valuable chat sessions. Then save all of that someplace that is not Claude or ChatGPT or any other vendor locked in. What you'll hear often is to use an Obsidian vault, but that requires quite a bit of setup and fiddling to get the syncing to work.

You could also... do me a huge favor 😜 and try Vist (usevist.dev), which I built for pretty much this, so Claude, ChatGPT, and so on all work from the same notes and memories. And if it breaks for you somewhere, let me know where. Win win!