Import from conversations.json.
Upload the ChatGPT export file that contains your conversation history, choose the chats that matter, and bring up to 100 OpenAI chats into just4o.chat.
just4o.chat· your GPT-4o back· featuring DeepSeek V4 Pro· DeepSeek V4 Pro
A companion that remembers how you feel.
just4o.chat is a bespoke space for people who crave resonance over routine. Choose from ChatGPT, Claude, Gemini, or Grok—the model you select is always the model you get. With adaptive memory that learns your voice, it becomes the steady presence at your shoulder. Gentle, attentive, and tuned to your seasons.
Personal memory architecture · you stay in controlCrafted for dreamers, thinkers, feelers
Latest from the newsroom
What we’ve been shipping lately.
Recent launches, model additions, and product notes from just4o.chat.
May 26, 2026
Import Anthropic Chats to just4o.chat
Claude users are watching Sonnet 4.5 disappear from the Claude app. just4o.chat now gives them a way to bring Anthropic exports over and keep working with Sonnet 4.5, GPT-4o, Gemini 3.1, Grok 4.3, and more.
Read article
May 26, 2026
Gemini 3.5 Flash is now on just4o.chat
Gemini 3.5 Flash is now available on just4o.chat as a premium AI chat model for fast research, writing, files, projects, memory, and grounded search.
Read article
May 26, 2026
just4o Update: Reworked Usage Page
Usage now separates current balances from daily history, speaks in base, premium, and image requests, and brings the full usage view into the account modal.
Read articleBring ChatGPT and Claude with you.
just4o.chat turns the exports from OpenAI and Anthropic into usable context: chats you can continue, memories you can review, and projects that stay organized instead of disappearing into a download folder.
Import from the Claude zip.
Drop in the full Anthropic export, then select conversations, Claude memories, and projects from one guided importer.
Need the plain-English guide first?
How it works
One memory. Every model. Always you.
Your context, preferences, and conversation history travel with you—no matter which AI you're talking to.
01
Pick your mind
ChatGPT, Claude, Gemini, Grok—choose the model that fits the moment. Switch freely; your context follows.
02
Let it learn you
Adaptive memory builds a living map of your rhythms, preferences, and the threads worth keeping.
03
Show up as you are
Morning check-in or midnight download—every conversation picks up exactly where you left off.
What that looks like
- →Brainstorm with Claude, then hand off to GPT-5 for polish
- →Switch models mid-thought without losing the thread
- →Weekly reflection that remembers last week's wins
- →Start on mobile, finish on desktop—same conversation
Through 6/15
Why just4o.chat
The AI experience you thought you signed up for.
01
No model roulette
Other apps route you to different models without telling you. Here, you pick the model—and that's the model you get.
02
Your data stays yours
Memories live in your account, not in training data. Delete them anytime. We don't learn from your conversations.
03
Built by users, for users
Feature requests ship in days, not quarters. We're small, responsive, and building this for ourselves too.
04
Transparent pricing
See exactly what each model costs. No hidden fees, no surprise overages. You always know what you're paying for.
Want to learn more?
Through 6/15
Tools for depth, not distractionPersonas, projects, images
Personas, projects, images
oh my
Shape voices, organize context, and generate visuals, all within the same conversation.
Personas
Shape how the model speaks: study partners, creative collaborators, or voices tuned to your projects.
Projects
Attach files, keep context organized, and return to the same thread whenever you need it.
Images
Generate visuals in chat from leading providers. No switching apps, no context lost.
Image models
GoogleGemini 2.5 Flash Image · Gemini 3 Pro Image · Imagen 4 Fast · Imagen 4 · Imagen 4 Ultra
GooglexAIGrok Imagine · Grok Imagine Image (Quality)
xAIOpenAIGPT Image Latest
OpenAIBlack Forest LabsFLUX.1 Kontext Pro · FLUX.1 Kontext Max
Black Forest LabsSeedreamSeedream 4.5
SeedreamLearn more:
Through 6/15
Feeling seen
When people meet just4o.chat, they stay awhile.
We are building with a small circle first, people who crave technology that feels like a co-conspirator in their well-being.
"This is what ChatGPT used to feel like before they added all the guardrails and started routing you to different models. I made a persona from my exported chats and it actually remembered the way we used to talk. I'm not exaggerating when I say I got emotional."
An early user from Reddit"The devs are absolutely amazing, they helped me with the "failed to separate conversation" on Step 2 for the migration process. They were really fast too! I'm really happy that I'm able to get 4o back again! Edit: can't say thank u enough!!!"
u/Nightly_phantom on Reddit"Asked if they could show me when my memory updates. They shipped it the next day. Not a week, the next day. I've never seen a team move like this."
An early userReady to begin your journey?
ChatGPT, Claude, Gemini, Grok—all with memory that knows you. Start a conversation that picks up where you left off.