How to Create Automatic Flashcards From a Class, PDF, or Video

Flashcards work because they force you to retrieve the answer before looking. The problem was never the method — it was the work of making the cards. Between writing the question on one side, the answer on the other, and reviewing in the app, a lot of people give up before they ever actually study.

With AI, that part gets out of the way. You hand over the source — a recorded class, a PDF, a video — and get back questions and answers ready to review. What’s left is the active studying, which is the part that matters.

Why flashcards beat rereading

Rereading creates the illusion of learning: the content feels familiar, so you think you know it. Flashcards reverse the process. You see the question, try to recall the answer, and only then check.

The difference isn’t one of style, it’s one of effort. Retrieving a piece of information leaves a stronger mark on memory than recognizing a ready-made explanation. That’s the testing effect, one of the best-documented strategies in the psychology of learning.

The second ingredient is spacing. Reviewing a card you just got right is a waste; reviewing it again days later, when the memory starts to weaken, is what consolidates it. Spaced repetition handles this on its own: what you get right goes to the back of the queue, and what you miss comes back sooner.

The flow: from source to review cards

1. Pick the source: a recorded class, a PDF, a video, or your own notes.
2. Let the AI generate the flashcards: questions and answers come from the content, not from a generic bank.
3. Review in short sessions: a few minutes a day, with the ones you miss coming back faster.
4. Return to the source when you’re stuck: use the transcript to check the original passage.

How to use Sintesy to create flashcards

Start from the New menu and pick the entry that matches your material. Upload an audio or video file, paste the URL of a YouTube video, or import an article. For a class you’re still going to watch, use the native recording.

When processing finishes, the synthesis brings together summary, transcript, and structure. From there, the flashcards appear as questions and answers generated from what was explained — not loose summaries. A law class turns into questions about concepts and cases. A physiology PDF turns into questions about mechanisms and exceptions.

If you’d rather control what goes into the cards, start from a specific passage. Open the transcript, find the hardest part, and ask the AI to turn that content into flashcards. You keep control over the focus; the AI handles the wording.

Build a review routine you can actually keep

Consistency beats intensity. A ten-minute session a day beats a Sunday marathon, because spacing needs time to work.

• Review little and often: the goal is to get things right, not to read everything at once.
• Let your mistakes guide the review: cards you miss come back sooner.
• Raise the difficulty gradually: start with direct questions, then move to comparisons and applications.
• Don’t make hundreds of cards at once: a small, well-reviewed set is worth more than an abandoned pile.

Check the source when the answer looks questionable

AI-generated flashcards are a strong starting point, but they don’t replace verification. When a card brings up a number, name, formula, or exception, go back to the transcript and check the original passage.

The searchable transcript helps: search for a related word, find the context, and adjust the card if needed. An inaccurate card, reviewed several times, fixes the error in place of the content.

When flashcards work best

They’re ideal for content packed with facts, terms, or definitions: languages, medicine, law, entrance exams, and technical subjects. They also work for locking in the steps of a procedure, as long as you build “what’s the next step” cards.

For concepts that require connecting ideas, combine flashcards with a mind map: the card fixes the fact, the map shows the relationship. For practical content, use scenarios and cases instead of dry definitions.

Study less, retrieve more

The value of a flashcard isn’t in the card — it’s in the habit of retrieving. When you trade rereading for questioning, studying stops being passive and starts leaving a trace.

With Sintesy, the tedious part — transcribing, summarizing, and writing the cards — happens on its own. What’s left for you is the work that actually locks in the content: answering, getting it wrong, reviewing, and answering again.