ChatGPT 教學：何時用 Project 取代一般對話，免於重複交代業務背景

Here's a habit I see in almost every small office that uses ChatGPT. Someone opens a new chat, pastes in a block of background ("We're a cleaning company, our tone is friendly, here are our prices, never promise same-day service"), and then asks the actual question.

Then they do it again the next morning. And the next.

It doesn't feel expensive because each paste takes a minute. But add it up across a team and a year, and it's hours. Worse, the pasted block drifts. One person has last spring's prices. Another forgot the "never promise same-day" line. Now two customers got two different answers from the same company.

The fix is a ChatGPT Project. Here's how I explain the difference.

Chat vs Project in one sentence

A chat is one conversation that starts blank. A Project is a workspace that keeps related chats, instructions and files together, so every new chat inside it already knows your business.

Use a chat for a one-off task. Use a Project for work you repeat: customer replies, quotes, a weekly report.

What actually changes inside a Project

	Regular chat	Project
Starts with	A blank page, plus whatever memory brings in	The Project's instructions and files
Instructions	Your custom instructions	Project instructions, which win over custom instructions
Files	Attached to that one chat	Added once under Sources, readable by every chat in the Project
Memory	Your account's memory settings	Default or project-only memory, chosen when you create it
Best for	One-off tasks	Repeated work for one business, client or job

The line that matters most for a business is the files row. You upload the price list once. Every chat in that Project can read it. When prices change, you replace one file instead of hoping everyone updates their copy-paste block.

A made-up example

In my lesson, a pretend house-cleaning company called Brightwater Cleaning gets a Project with three things: brand voice instructions, a price list, and a style guide.

A customer asks what a deep clean costs. The person answering types one line. The reply uses the right price and the right tone, and nobody pasted anything.

That's the payoff: the one-line request. Every rule that never changes lives in the Project. You only type what's different this time.

When a plain chat is still the right call

Not everything needs a Project. If you're proofreading one paragraph, brainstorming a headline, or asking a quick question, just use a chat. There's nothing to reuse, so the setup costs more than it saves.

My rule of thumb: if you've pasted the same background into three chats, it belongs in a Project.

How to set one up

These are the steps from my lesson. Menus change, so look for the same names on your screen.

In the sidebar, under Projects, click New project (or the + next to the Projects heading) and type a name.
Click Default memory and choose Project-only memory, then click Create project. On some accounts this sits behind a gear icon.
Click the ⋯ button next to Share, then Project settings, and paste your rules into Instructions. Click Save. Closing with the X doesn't save, which catches a lot of people.
Open the Sources tab, click Add sources, then Upload, and add files like your price list.
Start work in the New chat in box on the Project page.
Test it with a real request and check the answer against your price list.

Why project-only memory matters for client work

With project-only memory, chats inside the Project can draw on each other, but not on your chats outside it. And outside chats can't see the Project.

If you do work for several clients, that's the setting you want. Client A's details stay in Client A's Project. I'd usually set up one Project per client rather than one big Project for everyone.

Two things a Project doesn't do

It doesn't make the output safe to send unread. Instructions like "never invent a price" help a lot, but someone still reads every reply before it goes to a customer.

And it doesn't make private data safe to paste. Leave out what the task doesn't need, same as in any chat.

What about Custom GPTs?

For many small-business uses, a Project now does the same job. Custom GPTs are being retired, and moving one over is mostly copying the instructions, conversation starters and files into a Project. Check the dates for your own plan.

Try it free

I wrote the full comparison, with an FAQ and links to a free hands-on lesson, here: Chat vs Project in ChatGPT: The Difference for Work. The lesson takes about nine minutes. You set up the Brightwater Project yourself in a practice copy of ChatGPT, it checks each step, and nothing touches your real account.