Free to use. Pay for more.
Brain is free to use, for ever: notes, tasks, appointments, contacts and search cost nothing. You only add balance if you want more storage than the free allowance, or more AI once your free tokens are spent. No subscription, and no trial that ends.
What you get for free.
- A free allowance of AI when you sign up. About 500,000 tokens, roughly 380,000 words read and written. It is limited and does not renew every month: when it is spent, the AI waits until you add balance.
- 5.0 GB of storage, free for ever. Notes, tasks, contacts and the rest of the app never count against it, only files.
- Not a trial, not a subscription. Everything works for free for as long as you like. You add balance only if you want more AI or more storage, and no card is needed to start.
Add balance when you need it.
Four packs, the bigger the cheaper. Each one says how far it goes, at the price of the default model: $1 of balance is about 180,000 words read and written by the AI, and a cheaper model goes further. Balance never expires, and what you have not used of a purchase can be refunded within 14 days.
- $10 of balance about 1.8 million words of AI Pay $10.00
- $25 of balance about 4.5 million words of AI Pay $23.75 5% off
- $50 of balance about 8.9 million words of AI Pay $45.00 10% off
- $100 of balance about 18 million words of AI Pay $85.00 15% off
Prices are shown in US dollars. Once you sign up you see everything in your own currency. The price of a pack is what you pay, taxes included.
What the AI and the storage cost.
The AI is priced by million tokens, which is roughly 750,000 words. "In" is what you send it (your text and what it looks up) and "out" is what it writes back. You see every charge in your balance.
The default price, for any model not listed below: $3.00 in, $15.00 out.
Every price is what the provider charges for its API plus a 50% margin for Brain, and the same margin is on the storage.
See the price of every model (14)
| Model | In | Out |
|---|---|---|
| claude-haiku-5-5 | $0.15 | $0.75 |
| claude-haiku-4-5 | $1.50 | $7.50 |
| claude-sonnet-5 | $3.00 | $15.00 |
| claude-sonnet-5-5 | $3.00 | $15.00 |
| claude-sonnet-4-5 | $4.50 | $22.50 |
| claude-sonnet-4-6 | $4.50 | $22.50 |
| claude-opus-5-5 | $6.00 | $30.00 |
| claude-opus-4-5 | $7.50 | $37.50 |
| claude-opus-4-6 | $7.50 | $37.50 |
| claude-opus-4-7 | $7.50 | $37.50 |
| claude-opus-4-8 | $7.50 | $37.50 |
| claude-opus-5 | $7.50 | $37.50 |
| claude-fable-5 | $15.00 | $75.00 |
| claude-fable-5-1 | $15.00 | $75.00 |
Storage over 5.0 GB: $0.0345 a GB a month, charged every day from your balance.
Good to know.
- What happens when my balance runs out?
- The AI stops and you cannot add files over the free storage. Everything you have stays readable, downloadable and deletable for as long as you like. Nothing is ever deleted because of a low balance.
- Can I get a refund?
- Yes. What you have not used of a purchase goes back to the card you paid with, within 14 days of paying.
- Who pays in a team?
- The owner of a work group pays for what is in it: its files and the AI used on its content. Your own conversations with the assistant are paid by you.
- Who handles the payment?
- Stripe. Brain never sees your card number.