Learn anything. Remember it for years. Not just until tomorrow.
Books, articles, courses. Space quizzes you right before you'd forget, so what you learn actually stays.
Free on iOS, Android, Mac, Windows, Linux.
The bottleneck isn't input. It's retention.
You already consume enough. The attention economy made sure of that. The problem is that almost none of it compounds.
The feed trained you to forget.
The attention tax
Every platform on your phone optimizes for engagement, not memory. The habit is contagious: you start skimming books and articles the same way you scroll reels. Input goes up. Retention goes to zero.
Your notes app is a graveyard.
Capture ≠ retention
Highlighting, bookmarking, saving for later: it feels productive because it runs on the same dopamine loop as scrolling. None of it rewires memory. Passive storage gives you the illusion of knowing without the substance.
AI compounds daily. Your memory doesn't.
The asymmetry problem
Every model ships with more capability than the last. Your recall, judgment, and expertise stagnate inside an attention economy built to keep you scrolling past everything you meant to keep.
Retrieval gets it back
Built on decades of cognitive science.
Two techniques, 1,000+ studies, one algorithm tuned to your memory instead of your attention.
Active Recall
Every retrieval strengthens the neural pathway. Space forces retrieval. The single most effective learning technique ever measured.
Instead of re-reading, you actively reconstruct knowledge from memory. Each successful retrieval makes the next one easier and more durable.
FSRS-6 Spaced Repetition
Review at the precise moment before you forget. Not sooner. Not later. The timing is everything.
FSRS-6 is the most advanced open-source spaced repetition scheduler. It models your personal forgetting curve and adapts every interval to your memory. Peer-reviewed research shows it predicts recall more accurately than SM-2, the algorithm Anki has used since 1987.
Illustration coming soon
Your knowledge pipeline.
Three stages. One system. Compounding returns.
Ingest
Paste a URL, upload a PDF, snap a page. AI identifies the key concepts and turns them into structured cards in seconds.
Review
FSRS-6 schedules precision-timed reviews. Stuck on a concept? Get a contextual AI explanation without leaving the session.
Compound
Knowledge builds on knowledge. Ask follow-up questions, explore connections, watch retrievable expertise crystallize over weeks.
Other apps compete for your attention.
Space builds your memory.
vs. Note-taking apps
Notion, Obsidian, Roam capture information. Space makes you remember it. Capture without retrieval is storage, not learning.
- No retrieval practice built in
- No intelligent scheduling
- No forgetting curve awareness
vs. Legacy tools
Anki pioneered spaced repetition. Space modernizes it: FSRS-6 over SM-2, native AI, real-time sync across 5 platforms, and a UI that belongs on a modern phone.
- More advanced algorithm (FSRS-6)
- AI-powered knowledge extraction
- Native on every platform
vs. No system
Most professionals have no retention strategy. They rely on re-reading, bookmarks, and hope. Space replaces hope with science.
- Knowledge compounds, not just card count
- Algorithm handles scheduling
- Replaces hope with measurable retention
You own your learning. Forever.
Most apps let you export your cards. Space lets you export your entire learning history, so you can leave whenever you want.
All yours
Cards, reviews, and FSRS learning states. Your complete learning history, not just the content.
Export anytime
One space-cli command exports everything in open formats. No proprietary binaries, no manual workarounds.
No lock-in
Migrate to Anki or any other tool whenever you want. Your progress moves with you, not just your cards.
Trusted by professionals who take learning seriously.
"This is one of those apps that I remember installing when I buy a new phone. Also, beautiful app."
— App Store Review
"Exceptional Spaced Repetition app! 1000x better than your old friend Anki."
— App Store Review
"The best flashcard app I have ever used. The FSRS algorithm is incredibly effective for long-term retention."
— Google Play Review
"Finally a spaced repetition app that works on all my devices and looks great doing it."
— Mac App Store Review
Frequently asked questions
Is this just a flashcard app?
How much time does this take per day?
Is it free, and what does Pro add?
Can I import existing material?
Your knowledge, compounding.
Free on every platform. No credit card required.
