Synapse

Stop forgetting what you read.

Turn your book highlights into a living knowledge library.

Capture highlights from physical books by scanning pages, or sync your Kindle highlights to bring everything into one place. Save passages cleanly — without messy formatting or clutter.

As your library grows, the app automatically finds meaningful connections between ideas across books, even those you read months ago.

When you need clarity, just ask. Chat with your entire library to compare authors, revisit ideas, or rediscover insights you might have forgotten.

What you can do:

Scan pages from physical books and capture highlights instantly.
Sync and organize your Kindle highlights.
Save passages cleanly and keep them structured.
Discover hidden connections between ideas across books.
Get “flash insights” when new highlights relate to past reads.
Chat with your personal library to explore and recall knowledge.