How To Use Custom Instructions In Chat GPT

Custom instructions help you shape ChatGPT’s replies to fit what you need, like a personal guide for tone, detail, and content.

They make interactions more reliable and suited to your goals.

Custom instructions allow you to personalize ChatGPT’s responses for different needs and activities.

Here are some specific examples of how it might be used:

  • Writing Help: Produce writing that fits a specific style or voice, whether formal, laid-back, or argumentative. You could even design a unique character for the bot to emulate.
  • Study Aid: You can instruct Chat GPT to provide simplified explanations or breakdowns of complicated subjects to make learning easier.
  • Professional Communication: For writing tasks like emails, documents, or presentations, custom instructions help you match your company’s tone and rules.
  • Coding Assistance: If you’re a programmer, use ChatGPT for understanding code, solving errors, or writing in a particular programming language, adhering to certain standards.
  • Creative Writing: Set parameters for genre, storylines, or character traits, using ChatGPT to develop narratives or scripts.
  • Role-Playing: Instruct ChatGPT to simulate different scenarios or characters, often for creative fun or storytelling.
  • Language Practice: Those learning new languages can have conversations with ChatGPT or get explanations in simpler terms to improve specific linguistic skills.

Where are custom instructions found?

Custom instructions can be found by clicking your name in the lower left corner or the three dots beside your name.

The custom instructions screen in Chat GPT

Custom Instructions Vs. Conversations

Each time you choose “new chat” in Chat GPT, you create a new conversation.

Think of an individual conversation with ChatGPT like chatting with someone in the moment. You ask questions or talk about a topic, and ChatGPT responds right then based on what you’re saying. It’s like a back-and-forth text conversation where each reply is based on the last message.

Custom instructions, on the other hand, are like setting up rules for how ChatGPT should talk to you over time. You’re basically saying, “Whenever we chat, I want you to talk in this certain way, or focus on these kinds of details.”

It’s like giving ChatGPT a guidebook on how to interact with you before you start the conversation.

These instructions stick around, so even if you start a new chat later, ChatGPT remembers your preferences and applies them to the whole conversation.

Using Writing Personas In Custom Instructions

In past writings, I’ve shared that I’ve created a set of instructions for my bot “Bud.”

Anytime I use BUD, I’m using the voice, tone, style, and rules that I’ve established for it over time. These details are placed in my custom instructions.

However, because I use Chat GPT for many purposes, I don’t always want to be writing in the voice of BUD.

So how do I work around that?

In my custom instructions, I tell Chat GPT to ask me each time I start a new chat whether I want to write as BUD or not.

The screenshot below shows how I set that up and the beginning of the rules for the BUD persona.

Screenshot of my custom instructions in Chat GPT

Character Limits – How To Get The Most From Them

In a previous article, I wrote about creating attribute sets. This is where the voice, tone, style, audience, and rules information that I have in my own custom instructions come from.

Note that custom instructions only allow so many characters, so you’ll want to condense what you put in there.

As you build out your custom instructions, you’ll likely want to use far more characters than is allowed.

Ask the bot for help. Here’s how:

Outside of Chat GPT, get as detailed and specific as you can. Disregard the character count. Just put everything you can think of into the instructions. Then feed that copy to Chat GPT and tell it to condense to the character count you need without losing the meaning.

You’ll be amazed at how the bot can retain the essence of what you’ve said in far fewer words than we use.


Play with it. There are no absolutes here. Experiment and see what works for you.

Personally, I feed it things like:

  • I don’t like fluff or jargon
  • I prefer bullets with summaries
  • If you have questions, ask me one at a time

I modify the instructions each time I have an experience that I need to address. Either with things I really like and want more of – or – when responses are not what I like, and I can see a way to prevent it from repeating that output.

It’s a time saver for the small things that can take up much of my editing and formatting time.

Have fun with this. If you like humor, tell it to be sarcastic. If you like sports analogies, work that in. The possibilities are endless.