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Add what you are learning
Record a lecture or import a PDF, video, audio file, photo, or block of text.
Your material. Your study system.
Turn your learning materials into a study system that sticks.
BrainDen transforms lectures, PDFs, videos, audio, photos, and text into structured notes, flashcards, quizzes, mind maps, and active-recall practice.
Free to startNo card required32 supported languages
One learning loop
Create. Understand. Recall.
Independent educational review
Educational App Store Certified 20265.0/5
Evaluated for educational quality, safety, usability, and relevance.
Start with the material you already use
Lectures
PDFs
Videos
Photos
Text
From source to recall
Stop rebuilding your study system every time you open a new file.
BrainDen keeps the source, the note, and every way you practice together in one workflow.
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Get a note you can work with
BrainDen turns the material into a structured note while keeping the source attached.
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Practice until it sticks
Explain it back, review flashcards, take a quiz, or see the ideas as a mind map.
One connected note
Everything stays connected to what you learned.
Read the structured note, return to the source, then choose how you want to study next without switching tools.
- Source materials stay attached
- Highlights and comments stay in context
- Flashcards, quizzes, and mind maps are one tap away
Study actively
A note is only useful if it changes what you can remember.
Move from reading to retrieval with several ways to test, explain, and connect what you know.
Explain It Back
Find the gap between recognizing an idea and understanding it.
Teach the concept in your own words. Your study partner responds, asks follow-up questions, and shows you what to revisit.
Recall, do not just reread.
Review flashcards on a schedule, then use quizzes with immediate explanations to check your reasoning.
Mark the moments that matter.
Record a lecture, tag important sections while it is happening, and generate the note in your chosen language.
See how every idea connects.
Turn a long note into a mind map so the hierarchy and relationships become visible at a glance.
Built for serious reading
Read it. Mark it. Turn it into something you can recall.
Import a PDF, select the exact passage that matters, keep your own comment beside it, and continue studying from the same note.
- Choose a highlight color and keep your last choice
- Add a comment without losing the passage
- Create flashcards, quizzes, and explanations from the note
One account, every screen
Start on your phone. Keep going on a bigger screen.
Capture a thought on the move, review a note on your iPad, or settle in at your computer. BrainDen is available on iPhone, iPad, Android, and the web.
Questions, answered
Know what you are starting.
Need help with something else? Email hello@brainden.app.
What can I turn into a note?
You can start with a live recording, uploaded audio, a PDF, a video link, a photo, or your own text. BrainDen keeps the source with the note so you can return to it while studying.
Does BrainDen only summarize my material?
No. A structured note is the starting point. From there you can highlight and comment, generate flashcards and quizzes, build a mind map, translate the content, or use Explain It Back to test what you really understand.
What is Explain It Back?
It is an active-recall practice mode inspired by the Feynman Technique. You teach the idea in your own words and BrainDen points out what is clear, what is missing, and what to revisit.
Can I use BrainDen on more than one device?
Yes. BrainDen is available on the web, iPhone, iPad, and Android, so your study workflow can move with you.
Can I try it before paying?
Yes. You can create an account and make your first notes for free. No payment card is required to start.
Your next study session can start with material you already have.
Create your first note, then choose the way you want to understand and remember it.
Free to start. No card required.