Knowt's proposition is that flashcards shouldn't cost anything, and it's right. Heddy agrees, and then argues that the cards were never the hard part.
At a glance
| Knowt | Heddy | |
|---|---|---|
| Flashcards | Free | Free and unlimited |
| Study modes free | Learn, test, match | Spaced review, three grades |
| Import existing sets | Yes — including Quizlet | No |
| AI generation | Cards and notes from your material | Cards from your tutoring session |
| Spaced repetition across months | Limited | Yes, capped at 90 days |
| Can a card be finished? | No | Yes — mastered |
| Tutoring | No | Eight tutors |
| Subjects / age / region | Everything, any age | 7 subjects, 13+, UK |
| Best for | Free breadth, fast | Understanding what you got wrong |
What Knowt does better
It's free where it counts, and that's a real public good. Knowt's growth came from giving students the study modes that had moved behind a paywall elsewhere. A teenager without their own payment method can use the whole thing, and that matters more than product reviewers usually credit.
Importing your Quizlet sets is a genuinely thoughtful feature. Nobody wants to lose two years of decks to switch apps. Heddy has no import at all — your existing sets don't come with you, and that's a straightforward loss.
Generating cards and notes from material you paste in is fast and covers the case where the source is a lecture handout or a video rather than a lesson.
It covers every subject and every age. Heddy is seven school subjects, 13+, UK only. If you're doing A-level economics or you're eleven, Knowt works and Heddy doesn't.
If your problem is "I want free flashcards for everything, now", Knowt is the better answer and this comparison is over.
Where the two diverge
On what generation means. Both apps make cards for you, from different inputs, and the inputs matter more than the feature name.
Knowt generates from material — the notes or text you give it. Heddy generates from a lesson it just taught you: the professor writes the deck at the end of a session, with the error you actually made recorded on the relevant cards. Cards from material are about the subject. Cards from a session are about your gap. How that works.
There's also a quality asymmetry worth naming. Cards generated from pasted text inherit whatever was wrong or ambiguous in the source, and nobody checks. Cards written by a tutor who has just been working the problem with you are checked by construction.
On scheduling depth. Heddy runs proper spaced repetition across months, with two limits picked for school-age students — twenty cards a day, fixed, and a ninety-day interval cap so nothing disappears before a termly assessment. Cards can also be finished: known cold over months, a card becomes mastered and stops returning. Why that ending matters.
And on what happens at the fourth wrong answer. Knowt can produce an explanation. Heddy can hand you to the professor who owns the subject, with the card's front, back, hint and misconception already sent, so the conversation starts from a hypothesis rather than "what's confusing you?". That handover is the product.
That's the honest shape of the difference: an AI explanation is a paragraph, and a tutor is a conversation that refuses to give you the answer and walks you to it instead.
Which to choose
Knowt if you want free cards across every subject, you have Quizlet sets to bring, you're outside the UK or under 13, or the material you're revising from is handouts rather than lessons.
Heddy if you're a UK secondary student and the cards aren't the problem — the problem is that four of them keep beating you and no one has explained why.
Comparison written 10 Sep 2026 from each product's public description. Features and pricing change — check the current App Store listing before deciding. Written by Duke Harewood, who builds the tutors at aitutors.me.