Simple as that. Pay for what you use.
Monthly AI credits. Start free, expand when you need.
Free
Get started for free.
- 10 AI-generated cards/hour
- 50 AI-generated cards/month
- 5 YouTube videos/hour
- 5 PDFs/hour
- FSRS spaced repetition
- Professor Mode
Pro
For those who study intensively, with more credits and fewer blocks.
- 30 AI-generated cards/hour
- 300 AI-generated cards/month
- 15 YouTube videos/hour
- 15 PDFs/hour
- Rollover: up to 25% of balance (max. 500)
- FSRS spaced repetition
- Professor Mode
By using Duck, you agree to the Terms of Use and the Privacy Policy.
Why go Pro
More volume and study continuity
On Pro, the cost per AI action stays the same as Free. The difference is capacity: more credits per month, partial rollover of unused balance, and higher hourly limits to keep your study pace.
Monthly credits
4x more
Free: 500 credits/month
Pro: 2,000 credits/month
Credit rollover
Up to +500
On Pro, up to 25% of unused credits from the previous month roll over to the current month.
Rollover limit: 500 credits per cycle.
Monthly imports
No monthly limit
Free: 1 YouTube import and 1 PDF import per month.
Pro: no monthly import limit, respecting credits and hourly limits.
Frequently asked questions
Questions and answers
How do credits work?
Each AI action consumes credits: evaluating an answer costs 1 credit, generating a card set costs 10, importing from YouTube or PDF costs 20–30. Free gets 500 credits/month and Pro gets 2,000. On Pro, up to 25% of unused balance from the previous month rolls to the next cycle, capped at 500 credits.
What are Free monthly usage limits?
Beyond the credit budget, some features have monthly usage limits for Free users — like YouTube and PDF imports (1× per month each). Pro has no such limits.
Can I cancel anytime?
Yes. Cancel anytime from the subscription portal. You keep Pro until the end of the paid period.
What payment methods are accepted?
Credit card and PIX (when available in your region).
What happens to my data if I cancel?
Your decks and cards are preserved. Only credits revert to Free level (500/month).