# Custom instructions

> A standing note about who you are and how you want Claude to respond, saved once and applied to every chat automatically.

**Category:** Claude

**Custom instructions are a note Claude reads before every chat.** You set them once in your profile: your role, your preferences, the tone you like, anything you would otherwise retype each time. From then on Claude follows them everywhere, without you asking again.

They are the widest scope of [context](/glossary#context): a single [chat](/glossary#chat) is narrowest, a [project](/glossary#project) sits in the middle, and custom instructions apply to everything. **Use them for what is always true, and keep them short.**

## At work

Set once: 'I run ops at a logistics firm. Prefer short, plain answers in bullet points, no jargon.' Every chat now lands closer on the first try.

## Often confused with

Project instructions. Custom instructions apply to every chat; project instructions apply only inside one project.

## Related terms

- Context
- Project
- Claude

## See it in a lesson

[Giving Claude context](/en/learn/getting-started-with-claude/giving-claude-context)

## Further reading

- [Understanding Claude's personalization features (Help)](https://support.claude.com/en/articles/10185728-understanding-claude-s-personalization-features): Where to set instructions that apply everywhere.
- [Prompt engineering overview (Anthropic docs)](https://docs.claude.com/en/docs/build-with-claude/prompt-engineering/overview): Writing instructions that steer Claude well.
- [Introduction to Claude (Anthropic docs)](https://docs.claude.com/en/docs/intro): How standing context shapes replies.

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Last updated: 24/07/2026  
Source: Rollo Academy glossary