# How to Set ChatGPT Custom Instructions

> Custom instructions moved to Settings then Personalization, and it is now one field, not two boxes. They apply immediately to all chats, on every plan.

- Canonical: https://guides-ai.pages.dev/guides/chatgpt-custom-instructions/
- Plate 07.02 · Topic: ChatGPT (https://guides-ai.pages.dev/topics/chatgpt/)
- Published: 13 Jun 2026 · Updated: 06 Sept 2026 · 3 min read
- Source site: guides-ai — https://guides-ai.pages.dev/

Custom instructions let you state your context and preferences once and stop repeating them.
Two things changed since most guides were written: **it is now a single Custom Instructions
field rather than the old two boxes**, and instructions apply immediately to all chats — you no
longer have to start a new conversation for them to take effect.

## 1. Open Settings, then Personalization

Personalization no longer opens in its own modal. Go to **Settings → Personalization**, where
you manage the ChatGPT personality, custom instructions and Memory in one place, then click
**Custom Instructions**. It's available on all plans, on web, desktop, iOS and Android.

## 2. Turn on Enable customization

The toggle has to be on before anything you write is applied. This is the first thing to check
when instructions appear to be ignored.

## 3. Write context first, then output rules

You have one field, so give it a shape. Facts about you, then hard rules about the answer:

```text
Context: solo developer building small web apps with Astro and TypeScript,
deployed on Cloudflare. Assume an intermediate level; skip the basics.

Answers: be concise and direct. Give the answer first, then a short why.
Use code blocks for commands. No disclaimers, no "as an AI".
```

What it does: the top half colors *what* gets answered, the bottom half fixes *how*. Rules with
a testable shape ("answer first") survive; adjectives like "be helpful" do not.

You have room to be specific: **1,500 characters** on Free and Go, **5,000** on Plus, Pro,
Business, Enterprise and Edu. Instructions are not shared with people who open a shared link.

## Verify it worked

Ask something you know the model normally answers with a preamble. If the answer still opens
with three sentences of throat-clearing, check the toggle is on and cut the instruction down —
vague or over-long instructions are the usual cause, not a broken setting. You can edit or
delete them at any time and it only affects future conversations.

This is the consumer version of a [system prompt](/glossary/#system-prompt): standing text sent
ahead of every conversation. For per-project context rather than global preferences, use
[ChatGPT Projects](/guides/chatgpt-projects/); on the development side, the equivalent is a
[CLAUDE.md](/guides/create-claude-md-project-memory/).

Source: [ChatGPT Custom Instructions](https://help.openai.com/en/articles/8096356-chatgpt-custom-instructions).