Replace passive scrolling
Your phone is designed to capture your attention. Take it back: every time you open Cobalt is a step toward a sharper mind.
Learn from the best non-fiction books in minutes a day.
Scan any book with your phone.
Your attention is precious
Tap a book to read our full summary article.
Explore the key ideas of the greatest non-fiction books on our blog.
Your phone is designed to capture your attention. Take it back: every time you open Cobalt is a step toward a sharper mind.
Intelligence is synthesis. Expose yourself to the mental models of psychology, productivity and philosophy, and the dots connect.
In a world of shallow opinions, depth is a superpower. Bring perspectives nobody else has around the table.
There is a quiet assurance in knowing you progress every day. Competence creates confidence, not the other way round.
Curiosity is the engine of progress, and modern life dulls it. Reignite the urge to ask why.
Bad decisions come from a limited perspective. Build your mental toolbox, one summary at a time.
Explore by theme
Every Cobalt feature serves the same goal: ideas that stick.
Atomic Habits · Key idea
A 1% improvement per day leads to significant results over the long run. Instead of chasing radical transformations, focus on tiny daily adjustments. The key to success is not big changes but the consistency of small steps.
The essence jumps out, without rereading the same paragraph three times.
The summary adjusts to the time you have, the essence remains.
Your summaries follow you on planes, in the metro, everywhere.
Every summary you read joins your shelf.
Cobalt learns your reader profile and suggests what is next.
New titles join the library regularly.
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Our summaries are produced with the help of Cobalt, our artificial intelligence system specialized in analyzing and synthesizing books. The AI reads each book, identifies the key concepts and practical lessons, then structures them according to our reading method. Every summary is then reviewed and refined by our editors before publication, combining the speed of AI with the human eye.
Our summaries are designed to be read in 8 minutes on average. This duration has been optimized to maximize retention while respecting your precious time. Of course, you can take more (or less) time if you want to dig into certain concepts or take notes.
Cobalt works with a single subscription: Premium. It unlocks the entire app, all books, all summaries and every new feature, without any limit. The subscription is available monthly or yearly, starts with a free 7-day trial and can be cancelled at any time.
Of course! We value suggestions from our community. Anyone can propose a book directly from our website, whether you are a subscriber or not. Our team reviews every suggestion and prioritizes the most requested titles. If your suggestion is selected, you will be among the first to discover its summary.
Our summaries are designed to capture the essence and key lessons of a book, but they do not claim to replace the full reading experience. They serve three main purposes: helping you decide which books deserve your full reading time, letting you quickly absorb the essential concepts of many works, and offering reminders of the important ideas of books you have already read. Many of our users tell us they read more full books after discovering interesting titles through our summaries.
The ideas of the best books, in your pocket. Free to start.
