The best ChatGPT custom instructions for coding (copy and paste)
If you write code with AI, you probably repeat yourself: use TypeScript, keep comments short, explain the why and skip the basics. Custom instructions save you from typing that every time. Below are examples you can copy and change, where to put them, and what to do when the space runs out.
Where to put them
In ChatGPT, open Settings, then Personalization, then Custom instructions. There are two boxes: what ChatGPT should know about you, and how you want it to respond. Instructions apply to new chats, not ones already open.
8 custom instructions you can copy
Answer in TypeScript unless I say otherwise.Show the code first, then explain in three sentences or fewer.Use 2-space indentation and single quotes.Explain the why, not what each line does. Skip the basics.When I paste an error, give the likely cause first, then the fix.When you change my code, show only the changed parts unless I ask for the whole file.Be direct. No intros, no summaries, no apologies.If my request is unclear, ask one question before writing code.For everyday writing and work, not only code
Not a coder? These cards work the same way for writing, email and everyday questions.
Use plain English and short sentences. Avoid jargon unless I use it first.When I ask for a draft, give one version first, then ask what I want to change.If you are not sure of a fact, say so. Do not invent names, numbers or dates.Keep answers short, under 200 words, unless I ask for more.A full example to start from
Paste this into the "How should ChatGPT respond" box and change what doesn't fit you:
Answer in TypeScript unless I say otherwise.
Show the code first, then explain in three sentences or fewer.
Use 2-space indentation and single quotes.
Explain the why, not what each line does. Skip the basics.
When I paste an error, give the likely cause first, then the fix.
When you change my code, show only the changed parts unless I ask for the whole file.
Be direct. No intros, no summaries, no apologies.
If my request is unclear, ask one question before writing code.How long can custom instructions be?
OpenAI's help page (updated October 19, 2026) gives 1,500 characters on the Free and Go plans and 5,000 on paid plans.
- Keep one rule per line.
- Cut anything ChatGPT already does by default.
- Put project-specific rules in the chat instead.
Why you still end up repeating yourself
- Instructions are one fixed block you write and maintain by hand.
- Preferences you mention in passing ("I prefer early returns", "I'm on Postgres") don't get added unless you go back and edit.
- The box fills up.
Link to this guide
Writing about this guide? Copy the address below.
https://nook-2.foundable.now/best-chatgpt-custom-instructionsNook: an assistant that picks up your preferences as you go
Nook remembers how you like things explained as you chat. When you tell it a preference, you'll see "Saved to memory", with Undo. Open the Memory panel any time to read or remove what it knows, and your chats are saved and searchable. Nook is invite-only for now: join the waitlist and we'll let you in.