ChatGPT custom instructions that actually help
Set them once so you stop repeating yourself in every chat.
Updated 30 May 2026
Custom instructions are a small settings box where you tell ChatGPT, once, how you’d like it to respond. It then applies that to every new chat — so you’re not re-explaining your role, your audience, or your preferred style every single time.
The two boxes
ChatGPT asks two things: a little about you, and how you want it to respond. Keep both short and concrete. Vague preferences (“be helpful”) do nothing; specific ones change every answer.
What’s worth putting in
- Your context — “I’m a primary school teacher in the UK” reframes examples, vocabulary, and spelling automatically.
- Length and format — “Default to short answers; use bullet points for steps” stops the walls of text.
- Tone — “Plain English, no marketing language” is one of the highest-value lines you can add.
- What to skip — “Don’t add a summary paragraph at the end unless I ask.”
Treat custom instructions as your standing brief. Anything you find yourself typing in most chats belongs there instead.
The same habits behind a good one-off prompt — be specific, say who it’s for — apply here; see prompting basics.