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How to make ChatGPT write like you

Published October 22, 2026 · By Your Voice, Installed

ChatGPT drafts fast, but out of the box it writes in a default voice: polished, upbeat, and a bit like everyone else. If you've ever spent longer fixing a draft than it would have taken to write it, the problem usually isn't the tool. It's that ChatGPT doesn't know how you write.

You can fix that for free. The approach is simple: write down your voice as clear rules, then put those rules somewhere ChatGPT reads every time. This guide walks through both parts.

Why one-off prompts don't stick

Typing "write this in a casual, friendly tone" helps a little, but it has two problems. "Casual and friendly" means something different to everyone, and you have to repeat it in every chat. What works better is a standing set of instructions made of specific, checkable habits, such as "most sentences under 15 words," "open with the point, not a greeting," or "never say game-changer."

ChatGPT has two places to keep standing instructions:

  • Projects: a workspace with its own instructions, files and chats. Instructions apply only inside that project.
  • Custom Instructions: account-wide preferences applied to all your chats.

For writing in your voice, a Project is usually the better home. You can keep your voice rules separate from how you want ChatGPT to answer everyday questions.

Step 1: Collect 3 to 5 samples of your writing

Choose pieces that sound like you at your best: posts, emails, a newsletter, website copy. Different formats help ChatGPT separate your habits from the topic. Remove anything confidential and anyone else's personal details.

Step 2: Ask ChatGPT to analyze your voice

Start a new chat and paste your samples after this prompt:

Analyze my writing voice from the samples below. For each of these,
give 1-2 short quotes from my samples as evidence: sentence and
paragraph length, how I open, how I close, word choice, personality,
formatting habits, and what I avoid. Then write 10-14 specific
Do/Don't rules a writer could follow to sound like me. Don't invent
traits the samples don't support, and don't flatter me.

The "quote evidence" part is important. It keeps the analysis grounded in your actual writing.

Step 3: Edit the rules yourself

Read every rule critically. Delete anything that was a one-off. Then add what ChatGPT can't know from a few samples:

  • Your never list: specific words and phrases you don't want ("thrilled to announce," "unlock your potential").
  • Your readers, in one line.
  • Anything off-limits, like promising results.
  • A placeholder rule: "If I don't give you a date, price or name, write [placeholder] instead of inventing it."

If you want a structure to fill in, use the template in our voice guide article.

Step 4: Put it in a ChatGPT Project

Per OpenAI's help center, Projects are available to signed-in users (features vary by plan):

  1. In the ChatGPT sidebar, select New project and give it a name, such as "My Voice."
  2. Open the project, select the more options menu (•••), then Project settings.
  3. Paste your voice rules into the project instructions and save.
  4. Start new chats inside that project whenever you want something written in your voice.

OpenAI notes that project instructions apply only within that project and override your global custom instructions, which is exactly what you want here.

Source: OpenAI Help Center, Projects in ChatGPT.

Alternative: use Custom Instructions

If you want your voice everywhere in ChatGPT, use Custom Instructions instead. On web and desktop, OpenAI's steps are:

  1. Open Settings and select Personalization.
  2. Make sure Enable customization is on.
  3. Enter your rules in the Custom Instructions field.

On iOS and Android, the setting is under Settings → Customize ChatGPT. Custom instructions apply to all your chats, so if you also use ChatGPT for research or coding, a Project is usually cleaner. If the field feels cramped, use a shorter version of your rules with just the essentials.

Source: OpenAI Help Center, ChatGPT Custom Instructions.

Step 5: Ask for drafts the right way

Even with good instructions, the request matters. A few habits help:

  • One piece per message, with the reader and the goal: "A LinkedIn post for first-time founders about pricing your first offer."
  • Give it the facts. Dates, prices, names, links. Your placeholder rule keeps it from inventing them.
  • Ask for shorter than you think. It's easier to add a line than cut three.

An illustrative before and after

Here's a made-up example for a small bakery announcing new hours. This isn't output from a real account.

Without voice instructions:

"Exciting news! We're thrilled to announce extended hours so you can enjoy our delicious treats even more!"

With a voice guide that says "short sentences, no exclamation points, lead with the practical detail":

"We're open until 7 on Fridays now. Same bread, later pickup."

Step 6: Fix rules, not just drafts

When a draft sounds wrong, tell ChatGPT what's off. Then update the project instructions so it doesn't happen again. If it keeps using a phrase you hate, add it to the never list. If it's too formal, add a rule about contractions or sentence length. After a few rounds, drafts need far less editing.

Two reminders: always read before you publish, and never paste passwords, API keys or confidential client information into your instructions.

The same voice, beyond ChatGPT

Once you have a written voice guide, you're not locked into one tool. The same rules work as a Claude Skill, and in Gemini, Perplexity and Copilot.

Prefer a shortcut?

For a guided version of steps 1 to 3, grab the free Voice Primer. It's a ready-made prompt and checklist.

Or have it built for you. With Your Voice, Installed, you send 3 to 5 pieces you've already written, and you get ChatGPT instructions ready to paste into a Project, a Claude Skill, a portable voice guide, and setups for Gemini, Perplexity and Copilot, plus 3 sample pieces so you can judge the voice before installing anything. It's $39, one time, with one revision included.

Menu names and plan availability in AI tools change often. Steps here follow each company's help pages as of October 2026; check the linked sources if something looks different. Examples are illustrative.