New fact
A black hole with the Sun's mass would be only 6 kilometres across.
Small enough to cross on foot, if walking were still an option.
Turn “that's interesting” into “now I get it.”
Discover quick facts about subjects you care about. Pick one to explore in a short, interactive course, then review the key ideas before they fade.
No account required Free to start
Try it
Pick a reaction and meet your next fact.
Level 7
🔥 12⭐ 3,240
SpaceFor you
How Knowledge Loop works
Let Your Natural Curiousity Guide You
Start with what already has your attention and let the app turn it into learning material.
- 01
Find the spark
Choose topics you genuinely like. Swipe through useful, surprising facts and tell the app what lands.
- 02
Follow it further
Start a focused journey of short chapters.
- 03
Make it stick
Review interactives at expanding intervals, ensuring memory retention.
Start anywhere
Unlimited Learning
Follow countless topics, from black holes and ancient empires to Formula 1, anime, houseplants and jazz.
Built for wondering minds
Byte-Sized Lessons
Pick a topic you are interested in and the app builds a short journey around it. Each journey is a handful of chapters, and each chapter takes a few minutes: a quick explanation, then questions on what you have just read.
↗
Grounded before it is written
Each chapter is written from reference material gathered for that exact subject. Sources, diagrams and photographs are credited in the lesson, with key terms linked back to where they came from.
The science of learning
Scientifically Backed
Expanding Retrieval
Reviews given to you at precise times to ensure optimal memory retention.
Personal Interest
New material starts with something you already care enough to explore.
Active Recall
Quizzes, fill-the-blanks, timelines and flashcards make you retrieve or handle an idea instead of only reading it.
The Forgetting Curve
Every correct recall extends the time you will retain information exponentially.
2
After a year you still remember 16% of the material, against 12% with no review at all.
With reviewWithout review
Memory retained
Community
Learn With Friends
Build up your profile with learning achievements, compare progress, and easily share journeys.
Swipe through the ways your progress adds up.
🏆
Weekly leagues
Earn XP and climb the ranks in your league, the top ten move up each week.
🎖️
Profile Showcase
Collect badges, grow your level, track learning time and build a profile full of the subjects you have explored.
Keep the conversation going
Join the Knowledge Loop Discord
Meet other curious learners, share what you are exploring and help shape what Knowledge Loop becomes next.
Your next topic is waiting
What will you get curious about next?
Pick a topic, meet a fact and see where it takes you. Your next learning loop can start with anything that catches your attention.
Start learning freeNo account required. Use it in your browser or install the app later.
Good to know
Questions, answered.
The short version of accounts, AI, daily limits and custom topics.
Do I need an account to start?+
No. Start learning and an anonymous account is created automatically. Connect an email later when you want to save your progress across devices. Nothing is lost when you connect it.
How does signing in work?+
Enter your email, then type the 6-digit code we send you. There are no passwords or magic links, so signing in works the same way on web, Android and iOS.
How are the journeys created?+
An AI model writes each journey one chapter at a time around the subject you chose. Before writing, it receives reference material about that subject, so important details such as dates, names and numbers are grounded in a source.
What happens if I run out of my daily allowance?+
You can keep using every fact, journey and review already available to you. Only requests for brand-new material pause until the next day.
What if my topic is not listed?+
Use Add your own topic. It currently uses Wikipedia search to ground the topic.