# What should you do before GPT-4o leaves ChatGPT?

Date: 2026-02-05 · Author: Robert Scales · https://guidetoartificialintelligence.com/en/learn/before-gpt-4o-leaves-chatgpt/

**Answer:** Before February 13, 2026, list what you still use GPT-4o for, save the prompts and answers you rely on, and run the same prompts on GPT-5.2 now while you can still compare the two side by side. Then adjust ChatGPT's personality settings and your custom GPTs' instructions until the new answers match what you need.

On February 13, 2026, OpenAI will remove GPT-4o from ChatGPT, along with three other older models (o4-mini and both versions of GPT-4.1), on the same day the older GPT-5 Instant and Thinking models go. After that date, conversations that used those models continue on GPT-5.2. Nothing changes in the API for now, and ChatGPT's voice mode and image generation are not affected: they use related but separate models.

OpenAI says only about 0.1% of users still pick GPT-4o each day. If you are one of them, you probably chose it for a reason, often its conversational style or the way it handled creative brainstorming. You have about a week to make the move on your own terms rather than discover the difference in the middle of a task.

## A one-week checklist

**1. Write down what you use GPT-4o for.** Be specific: "drafting newsletter intros in a casual voice," "brainstorming names for products," "a custom GPT that answers questions about our club rules." Most people find three to six recurring tasks.

**2. Save the prompts and answers you rely on.** For each task, copy one or two prompts that work well, and the answers you were happy with, into a document. These become your test set. If you want a complete archive, ChatGPT's settings include an export option that emails you a file with your conversations.

**3. Compare now, side by side.** Open a new chat, choose GPT-5.2, and paste in the same prompt. Keep both answers next to each other. This is the step that is impossible after February 13, because the old model will no longer be there to compare against.

**4. Note what changed, in a few words.** "Longer." "More formal." "Fewer ideas, more polished." A short label makes the fix obvious.

**5. Adjust the settings, then the prompt.** OpenAI says feedback from GPT-4o users influenced its recent releases, GPT-5.2 and the earlier GPT-5.1, and that you can now choose a base style and tone, such as Friendly, and adjust traits like warmth and enthusiasm in ChatGPT's personalization settings. Try those first; they apply to every chat. If one task still feels off, add a sentence to that prompt.

Here is what a filled-in comparison might look like. The entries are illustrative.

| Task | Difference on GPT-5.2 | Fix |
|---|---|---|
| Newsletter intros | A bit more formal | Friendly style, higher warmth |
| Product name ideas | Fewer, safer names | "Give me 20 ideas, including some unusual ones" |
| Club rules GPT | Longer answers | "Answer in three sentences or fewer" added to its instructions |

To speed up step 4, you can ask the model to describe the gap for you:

```prompt
Below are two answers to the same prompt. Answer A is the style I want; Answer B is what I got.
Describe in five bullet points how B differs from A in length, tone, structure and word choice.
Then write one or two sentences I could add to my prompt so future answers read more like A.

Prompt: [paste]
Answer A: [paste]
Answer B: [paste]
```

> **Try it:** Pick the one GPT-4o conversation you would miss most, rerun its first prompt on GPT-5.2 today, and save both answers in the same note with a one-line label for the difference.

## What happens to your chats and projects

You do not need to rescue old conversations. OpenAI's help page says existing projects and chats stay as they are until February 13 and can then be continued with other models. What changes is only the model that writes new replies. If a long-running chat depends heavily on GPT-4o's earlier tone, it may help to start a fresh chat after the switch and paste in a short summary of where you were.

If you use GPT-4o through the API in an app or script, nothing changes yet. OpenAI has said it will give advance notice before retiring models there.

## How do you move your GPTs and habits to a newer model?

**Custom GPTs** keep running until February 13; on that day their default model becomes GPT-5.2 and new messages use it. That makes this week a good time to test them. Open each GPT you depend on, run your saved test prompts, and keep the answers. Then copy the GPT's instructions into a new chat on GPT-5.2, add the same test prompt, and see how it behaves. Where it drifts, tighten the instructions: a clear sentence about length, tone or format usually does more than a long explanation. If you share a GPT with others, tell them the switch is coming and ask them to report anything that feels different.

**Habits** take a little longer. Many GPT-4o users developed prompts that relied on its particular defaults, such as a chatty opening or a certain kind of enthusiasm. Rather than recreating those defaults in every prompt, set them once: choose a base style, adjust warmth and enthusiasm, and use custom instructions for anything you always want, such as "use Canadian spelling" or "keep lists short."

Then give yourself a short adjustment period. Rerun your test set once more a week after the switch, because first impressions of a new model are often shaped by one or two unusual answers. The goal is not to make GPT-5.2 imitate GPT-4o perfectly, but to get the results you need from the model that ChatGPT will be using.

## Sources

- Retiring GPT-4o, GPT-4.1, GPT-4.1 mini, and OpenAI o4-mini in ChatGPT: https://openai.com/index/retiring-gpt-4o-and-older-models/
- Retiring GPT-4o and other ChatGPT models: https://help.openai.com/en/articles/20001051-retiring-gpt-4o-and-other-chatgpt-models
- New ways to manage your data in ChatGPT: https://openai.com/index/new-ways-to-manage-your-data-in-chatgpt/