# Make ChatGPT Write Like Me: Samples, Settings and Tests (2026)

> Give ChatGPT three to five samples, a style recipe with real numbers and a project to keep them in, then test it against a piece you wrote yourself.

Source: https://hidengpt.com/guides/how-to-make-chatgpt-write-like-you

# How do I make ChatGPT write like me?

Updated October 10, 2026

· 8 min read · by the HidenGPT team

To make ChatGPT write like you, give it three to five samples of your own writing, a short style recipe that describes your habits in numbers, and a place to keep both, such as Custom Instructions or a project. Then test it against a piece you already wrote and fix whatever drifts.

Samples show habits you would never think to describe. The recipe carries those habits into every chat. Your own facts, given fresh in each request, do the rest, and the last read is still yours.

| Place | What it keeps | Limits and notes | Use it for |
|---|---|---|---|
| Pasted into one chat | Samples and notes for that conversation only | No setting involved; you paste them again in each new chat | Trying a recipe before you save it |
| Custom Instructions | Text ChatGPT considers in every chat | 1,500 characters on Free and Go; 5,000 on Plus, Pro, Business, Enterprise and Education | A short style recipe that is true of all your writing |
| A project | Chats, files and project instructions kept together | Project instructions override your Custom Instructions inside the project; 5 files per project on Free, 25 on Go and Plus, 40 on Pro, Business, Enterprise and Edu | Samples as files plus a fuller recipe, one project per kind of writing |
| Memory | Preferences and details picked up across chats | Varies by plan, region and settings; ChatGPT decides what is relevant | Small preferences, not a whole style |
| A custom GPT | Instructions and up to 20 knowledge files | New GPTs can't be created on personal accounts (Free, Go, Plus, Pro); custom GPTs are scheduled to retire on 11 December 2026 | Only one you built before; plan to move it |

## Step 1: Collect three to five samples that are really yours

Pick pieces you wrote without AI help and close to the job: old emails if you want emails, past posts if you want posts, essays if you want essays. Three to five pieces of 300 to 800 words each is plenty (a rule of thumb, not a measurement). Anthropic's prompting guide suggests 3 to 5 examples for steering Claude's tone, and OpenAI's page on building GPTs tells builders to include brief examples too. The advice carries over to an ordinary ChatGPT chat.

Leave out anything co-written, rewritten by a grammar tool or written for a very different reader. A eulogy and a Slack message share almost no habits, so mixing them gives you an average of both.

Label each sample with who it was for, such as “email to a client I've worked with for two years”. Style shifts with the reader, and the label tells ChatGPT which version of you to copy.

## Step 2: Write a style recipe with numbers, not adjectives

“Casual but professional” means something different to everyone. Numbers don't. Take ten sentences from your samples and count the words in each. A worked example: 6, 14, 9, 21, 4, 12, 17, 8, 11 and 13 words, which is 115 words in all, an average of 11.5 and a range from 4 to 21. The range matters as much as the average, because runs of same-length sentences are one of the things that make a draft read as generated.

Then note five more habits: whether you use contractions, how you open (straight to the point or with a line of context), how you close (a next step, a question, nothing at all), three words you use a lot and three you never use, and your punctuation (parentheses, semicolons, dashes).

Turn the notes into a recipe. This one is 537 characters, short enough for any plan's Custom Instructions:

“Write like me. My sentences average about 12 words, from 4 to 21, and I mix short ones with long ones. I use contractions. I open with the point, never a greeting line, and I end with the next step, never a summary. I say ‘use’, ‘but’ and ‘I think’. I never write ‘utilize’, never start a sentence with ‘However’ and never write ‘I hope this finds you well’. Paragraphs are two or three sentences. I use parentheses for asides and no semicolons. Copy my style from the samples, never their content, and never add facts I didn't give you.”

## Step 3: Save it where ChatGPT will use it

Custom Instructions are the simplest home. On the web or the desktop app, open Settings, then Personalization, check that Enable customization is on and paste the recipe into the Custom Instructions field; on iOS and Android the menu is called Customize ChatGPT. They apply to every chat. OpenAI caps them at 1,500 characters on Free and Go and 5,000 on Plus, Pro, Business, Enterprise and Education, so a recipe fits and samples mostly don't.

Samples belong in a project. Select New project in the sidebar, upload your samples as files or paste them as text, then open the ••• menu, choose Project settings and paste the recipe as the project's instructions. OpenAI says project instructions apply only inside that project and override your global Custom Instructions, so write them to stand on their own. One project per kind of writing (work email, newsletter, cover letters) keeps the samples from blending.

Two settings people expect to help do less. The personality picker, Base style and tone, changes how ChatGPT talks to you, but OpenAI's help page says an email, post or résumé you ask for follows your instructions and the context, not necessarily the personality. And a custom GPT is off the table for most people: OpenAI's help pages say personal accounts (Free, Go, Plus and Pro) can't create new GPTs, and custom GPTs are scheduled to retire on 11 December 2026.

## Step 4: Test it against something you already wrote

Pick a piece you wrote that isn't one of the samples, such as an email from last month. Strip it down to the bare facts in a few notes, with none of your wording, and ask ChatGPT, inside the project, to write it from those notes. Put the two side by side and score five things: average sentence length within about 3 words of yours (a rule of thumb), the same kind of opening, the same kind of ending, no word you never use, and no fact you didn't give.

A worked example. Your original: 118 words in 10 sentences, an average of 11.8, opening with the request. ChatGPT's version: 164 words in 9 sentences, an average of 18.2, opening with “I hope you're doing well”. That fails length and opening, so it scores 3 out of 5 at best. The fix is one more line in the recipe (“keep emails under 130 words and open with the request”) and a short sample that shows it.

The decision rule: 4 or 5 out of 5, keep the setup. 2 or 3, add each missed habit to the recipe as its own line. 0 or 1, the samples are probably the wrong kind of writing, so replace them before you touch the recipe.

## What still goes wrong, and where a dedicated tool fits

Even a good setup slips in predictable ways.

Drift: deep into a long chat, the replies slide back toward ChatGPT's usual phrasing. Start a new chat in the project rather than correcting the same thread again and again.

Caricature: it overdoes a habit. You put one aside in parentheses in an email; it puts five. Add a limit, such as “at most one per piece”.

Borrowed content: it lifts an anecdote or a phrase from a sample. The “never their content” line helps; check anyway.

Invented details: told to sound like you, it fills gaps with plausible facts about your life. Give it the facts and ask it to mark anything missing with [CHECK].

Stock phrases: words like “delve” or “plays a crucial role” creep back in. A short avoid list at the end of the recipe keeps most of them out.

If you would rather not maintain samples and a recipe by hand, a dedicated writing tool can hold them for you. HidenGPT, for example, builds a voice profile from 2 to 5 pieces of your writing (300 characters at least), drafts in it and runs a red pen that cuts stock phrases; saved voices need a paid plan. Like ChatGPT, it can't supply what only you know, so the facts and the last read stay with you.

## Common mistakes

- Pasting a single sample: give three to five pieces of the same kind of writing.
- Describing yourself in adjectives: count your sentence lengths and name the words you use and the ones you avoid.
- Using samples a tool helped write: pick pieces you wrote alone, or ChatGPT learns the tool's habits instead of yours.
- Mixing kinds of writing in one project: keep work email, posts and essays in separate projects.
- Leaving the facts out of the request: give names, numbers and details, or it invents plausible ones.
- Trusting the setup untested: score one draft against a piece you already wrote.

## Questions

### Can ChatGPT learn my writing style?

It can imitate it, as long as your samples and instructions are in front of it. ChatGPT follows what you paste into a chat, upload to a project or save in Custom Instructions; it doesn't leave one conversation knowing how you write, unless memory happens to keep a preference.

### What prompt makes ChatGPT write like me?

Paste three samples, then write: “Study these for sentence length, word choice, how I open and how I close. Write [the task] in the same style, using only the facts below. Copy the style, not the content.” Add your style recipe and the facts. For repeat use, save the recipe in Custom Instructions or a project.

### How do I train ChatGPT on my writing style?

There is no training step you can run on your own writing in ChatGPT. What works is the setup on this page: samples in a project, a style recipe in its instructions and a test against something you wrote. A saved project is the closest thing to a trained copy.

### How many writing samples should I give ChatGPT?

Three to five, each 300 to 800 words, is a sensible start (a rule of thumb). One sample gives it too little to generalize from, and a pile of mixed pieces blurs the style. Anthropic's prompting guide suggests 3 to 5 examples for Claude, and the same range is a fair starting point for ChatGPT.

### Can I still make a custom GPT that writes like me?

Not on a personal account. OpenAI's help pages, read on 10 October 2026, say Free, Go, Plus and Pro accounts can't create new GPTs, existing GPTs keep working until retirement, and custom GPTs are scheduled to retire on 11 December 2026. A project with your samples and instructions covers most of what a personal style GPT did.

### Why does ChatGPT still not sound like me?

Usually because the samples are mixed, the request has no real facts or the chat has run long. Use samples of one kind of writing, give it the specifics only you know, and start a fresh chat in the project when the replies begin to drift.

### Does the personality setting make ChatGPT sound like me?

No. Personalities such as Professional or Friendly change how ChatGPT talks to you, and OpenAI says drafts like emails and résumés follow your instructions and the context instead. Your samples and recipe are what move it toward your voice.

## Sources

- [OpenAI Help Center: ChatGPT Custom Instructions](https://help.openai.com/en/articles/8096356-chatgpt-custom-instructions) (checked October 10, 2026)
- [OpenAI Help Center: Projects in ChatGPT](https://help.openai.com/en/articles/10169521-projects-in-chatgpt) (checked October 10, 2026)
- [OpenAI Help Center: Customizing your ChatGPT personality](https://help.openai.com/en/articles/11899719-customizing-your-chatgpt-personality) (checked October 10, 2026)
- [OpenAI Help Center: Memory in ChatGPT](https://help.openai.com/en/articles/8590148-memory-in-chatgpt) (checked October 10, 2026)
- [OpenAI Help Center: Creating and editing GPTs](https://help.openai.com/en/articles/8554397-creating-and-editing-gpts) (checked October 10, 2026)
- [OpenAI Help Center: Custom GPT retirement and migration FAQ](https://help.openai.com/en/articles/20001519-custom-gpt-retirement-and-migration-faq) (checked October 10, 2026)
- [Claude Platform Docs: Prompting best practices](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/claude-prompting-best-practices) (checked October 10, 2026)

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