Customization
Stopre-teachingeverynewchat
Built for people who are tired of generic replies, tone drift, and restating the same context every time. Customization is the persistent control layer for how just4o.chat should talk, structure answers, and ground itself in your world.
What this fixes
- Set the assistant baseline once instead of rewriting the same prompt every session.
- Control tone, structure, and writing style so replies stop drifting back to bland defaults.
- Carry personal context and reusable files across chats without copy-pasting the same background.
Account
Customization
Why it matters
Visible settings, not mystery behavior
The frustration behind a lot of modern chat usage is not lack of intelligence. It is lack of continuity. This page exists to make your baseline explicit, persistent, and editable.
Persistent preferences
The complaint is always the same: a new chat means starting over. Customization keeps your baseline alive across new conversations.
Visible controls
No mystery personality layer. You can see the fields, edit them directly, and understand what is shaping the response.
Reusable context
Profile details and global files make the system feel prepared before you even send the first message.
Control surface
Every customization layer has a job
This is not one vague "make it sound more like me" slider. Each control shapes a different part of the runtime so you can be precise about what should persist.
Behavior layer
Custom Instructions
This is the freeform field for hard rules, recurring asks, and guardrails you are tired of repeating.
- Up to 1500 characters for your baseline operating instructions.
- Ideal for directness, depth, formatting, or "challenge my assumptions" preferences.
- Best when you want every new chat to start from your standards instead of the model's default posture.
Reading experience
AI Response Font
The output is not just what the model says. It is also what it feels like to read all day.
- Pick the font used for AI responses in chat.
- Small detail, big payoff when you live in the product for hours.
- Useful for making long answers feel more readable and more "yours."
Voice layer
Tone & Style
Set a base tone, then shape the texture of the output instead of hoping the model guesses correctly.
- Choose a base tone like Socratic, Direct, Friendly, Concise, or Thoughtful.
- Adjust Warmth, Enthusiasm, Headers, Lists, Tables, and Emojis individually.
- Browse writing style by category, region, or era and choose a voice like Montaigne when you want stronger flavor.
Personal grounding
About You
Nickname, occupation, and a richer "More About You" field give the system lightweight context about who it is talking to.
- Helpful for recurring work identity, communication preferences, and domain background.
- Cuts down on re-explaining your role, project, or preferred interaction style.
- Lets replies feel more situational without turning every prompt into autobiography.
Portable context
Global Files
Upload files that should matter in every chat, not just one thread or one project.
- Applies across chats so core docs stay available wherever you work.
- Great for reference docs, voice guides, strategy notes, or evergreen knowledge.
- The AI can pull relevant context from those files when it matters.
Persistence
Customization travels with you
Once saved, your account baseline carries into future conversations. That means less prompt overhead, fewer resets to neutral, and a much better starting point before the model even sees your first message.
If you deliberately switch into a persona, that persona can supersede the default customization layer so the system avoids mixed signals.
Set the baseline in Account
Account > Customization is the home for instructions, profile content, font, tone, and global files.
Start a new chat without re-prompting
New conversations inherit that baseline, so the assistant starts closer to your preferred style and structure.
Bring identity and documents with you
About You and Global Files travel across chats, giving the system more useful context before the conversation deepens.
Override on purpose, not by accident
If you switch into a persona, that persona can supersede the default customization layer so behaviors do not clash.
Set the baseline once. Stop burning prompts on it forever.
Save your instructions, tune the voice, attach your files, and make new chats start from your reality instead of generic defaults.