Guide
Custom instructions vs. a Carrierfile
Short answer
Custom instructions are a settings box inside one AI product. A Carrierfile is a plain-text file you own. It holds the same kind of instructions plus your projects, named tones, approved memories, and a session log, and it works in any AI. Use custom instructions for quick defaults in one app; use a Carrierfile when you want your context to be complete, editable, and portable.
Side by side
| Custom instructions | Carrierfile | |
|---|---|---|
| Where it lives | Inside one AI’s settings | A text file you keep |
| Works in | That one product | Any AI you can paste text into |
| Plan | Features and limits depend on your plan | Works the same on any plan, including free |
| What it holds | A short description and preferences | Who you are, how you work, projects, tones, memories, session log |
| Grows over time | Only if you edit it | Yes. “Pack up” proposes updates you approve |
| Switch styles | Edit the settings | Say “switch to Editor” mid-chat |
| Who owns it | The platform stores it | You do |
| Cost | Included with the product | Free, open format |
When custom instructions are enough
If you only use one AI and just want it to stop over-explaining, custom instructions are quick and fine. A couple of lines like “Assume I’m competent. Keep answers short” go a long way.
When you want a Carrierfile
- You use more than one AI, or you might switch.
- You work on ongoing projects and want the AI to pick up where you left off.
- You want to see and edit everything the AI “knows” about you, in one place.
- You want different working styles for different jobs, like a blunt editor for drafts and a patient tutor for learning something new.
Use both
They don’t conflict. Many people keep a one-line custom instruction and paste their Carrierfile in when they start real work. The file is the part that comes with you.
Questions people ask
What are custom instructions?
Custom instructions are a settings feature in AI assistants like ChatGPT where you describe yourself and how you want responses. They apply only inside that product.
Is a Carrierfile a replacement for custom instructions?
It can be, but it does not have to be. A Carrierfile holds everything custom instructions do, plus projects, tones, memories and a log, and it works across every AI.
Can I paste my custom instructions into a Carrierfile?
Yes. Put them in the working-style step of the builder, or edit the How We Work section of the file directly.
Build your Carrierfile. It takes about five minutes, runs entirely in your browser, and works in any AI. Free, no account.
Build yours →