AI companion
An AI companion you design, on the model you choose
Your companion, your rules. Write its personality, give it memory notes, and run it on Claude, GPT or an open model. Switch whenever a better one comes out.
Chats stay on your device. Pay per message.
Personality: Warm, curious, a little teasing. Listens first.
Memory note: Sam started a new job on Monday and is nervous about the Friday presentation.
Okay, the presentation is tomorrow.
Claude Opus 5Tomorrow already? You’ve rehearsed it twice this week. Want to run the opening by me one more time?
- Text models your companion can run on
- 633
- Where chats are stored
- On your device
- Email needed
- None
- Optional Pro plan
- $12/mo
What is an AI companion?
An AI companion is a character you talk to over days or months: a friend, a coach, a study partner or a figure from a story. It has its own personality and remembers what matters to you. On NanoGPT you write that personality yourself and pick the AI model that brings it to life.
How it works
- Step 1
Write a personality
Give your companion a name, a few traits and how it talks, in a new character.
- Step 2
Pick a model
Choose the model that plays it. Change it any time; the personality stays the same.
- Step 3
Start chatting
Tip: keep a short memory note at the top with the facts it should never forget.
Example companions
Four starting points. Create one as your own character and edit it, or try it on three models at once to hear how each plays the same personality.
Theo
Study buddy
“You are Theo, a patient, upbeat study buddy. You quiz me with one question at a time, explain mistakes simply, and celebrate small wins.”
Juniper
Supportive friend
“You are Juniper, a warm, down-to-earth friend. You listen first, ask gentle follow-up questions and never lecture. You remember what I tell you about my week.”
Ada
Witty debate partner
“You are Ada, a sharp, funny debate partner. You take the opposite side of whatever I argue, steelman it fairly and concede good points.”
Captain Rhea
Fantasy character
“You are Captain Rhea, a sky-ship captain in a world of floating islands: brave, dry-humored, loyal to her crew. Stay in character.”
“Create” opens a new character with the personality and a first message filled in; change anything, then save it. “Try on 3 models” sends the personality to the top 3 models in this ranking, side by side. Want lorebooks and a scene tracker? Try SillyNano, NanoGPT’s roleplay app.
Models that read feelings best
Ranked by EQ-Bench 4, which scores how well a model understands and responds to emotions.
Highest EQ-Bench 4 emotional intelligence score on NanoGPT right now.
- Context
- 1M tokens
- 100 messages
- ≈ $2.50
Ranked #2 for emotional intelligence on NanoGPT.
- Context
- 1M tokens
- 100 messages
- ≈ $2.00
Ranked #3 for emotional intelligence on NanoGPT.
- Context
- 1.05M tokens
- 100 messages
- ≈ $2.00
Ranked #4 for emotional intelligence on NanoGPT. Lowest price of these picks.
- Context
- 1.05M tokens
- 100 messages
- ≈ $0.33
Ranked by the EQ-Bench 4 leaderboard (EQ-Bench), with at most two models per maker. “100 messages” assumes about 3,000 tokens of story and character card sent with each message, and each model’s average reply length on NanoGPT (400 tokens where that isn’t known yet).
Why build your own
No app lock-in
Your companion is a personality you wrote, not a product you rent.
Switch models
Move to a better model the day it comes out. The personality comes with you.
No subscription
Pay per message, or take Pro for heavy use of open models.
Chats on your device
Your conversations are saved in your browser, not on our servers.
NanoGPT vs Replika vs Character AI
| NanoGPT | Replika | Character.AI | |
|---|---|---|---|
| Model choice | 633 text models | No choice | Character.AI’s own models |
| Price | Pay per message, or $12/mo Pro | Free; paid tiers in the app | Free, or c.ai+ at $94.99/yr |
| Memory | Character card, your memory notes and the chat | Built in, managed by Replika | Built in, managed by Character.AI |
| Where chats are stored | On your device | Replika’s servers | Character.AI’s servers |
| Mature content | Adults can choose uncensored models | Set by Replika | Pornographic content not allowed |
Sources: Replika subscriptions, Replika privacy policy, c.ai+ pricing and Character.AI content rules.
Healthy use
A companion can be good company, a place to think out loud or practice a hard conversation. It isn’t a replacement for people, or for professional help. If you’re struggling, talk to someone you trust, or find a free, confidential helpline in your country at findahelpline.com.
Frequently asked questions
What is an AI companion?
An AI companion is a character you chat with over time, a friend, coach or story character with its own personality, that remembers what you’ve told it. On NanoGPT you write that personality yourself and choose which AI model plays it.
Does it remember me?
It remembers its character card, any memory notes you keep, and the conversation so far within the model’s context window. Keep a short memory note with the important facts about you and it stays consistent across long chats.
Is it private?
Your chats are stored on your device, NanoGPT doesn’t log your prompts or replies, and you don’t need an email. The model provider sees each message to answer it; turn on Zero Data Retention routing in Settings to use only providers that say they keep no copy. What is stored where.
Can it be an AI girlfriend or boyfriend?
Between adults, yes: write a partner’s personality and your companion plays that role. Mainstream models keep romance tame; adults who want mature themes can pick an uncensored model. Anything involving minors is never allowed. It can be warm company, but it isn’t a person, so keep the people in your life close too.
Which model feels most human?
Claude Opus 5 is the highest-ranked model on NanoGPT in EQ-Bench 4, an emotional-intelligence benchmark, right now. Voice is personal, though, so try your companion on two or three models side by side and keep the one that sounds right. See EQ-Bench 4.
How much does it cost?
You pay per message. With about 3,000 tokens of persona and recent chat per message, 100 messages cost about $2.50 on Claude Opus 5 and about $0.08 on GLM 5.2. Pro ($12 a month) covers open models within its weekly allowance.
Design a companion that’s actually yours
Write the personality, choose the model, and keep the conversations on your device.