Your thoughts connected in real time.
A non-linear second brain mapping ideas across bidirectional nodes as fast as you think.
Bidirectional association layer that synthesizes disparate concepts.
Trusted by researchers and engineers from
Knowledge as a living neural network.
Folders force artificial hierarchies onto fluid thoughts. Synapse links ideas associatively based on conceptual distance and citation paths.
Bidirectional Backlinking
Every link creates an automatic reverse portal. Traverse connected thoughts forward or backward without broken paths.
Semantic Surface Retrieval
When writing a thesis or paper, Synapse automatically suggests forgotten notes with matching conceptual vectors.
Plain Markdown On Disk
No proprietary database lock-in. Your notes remain plain text files on your local drive, compatible with Git and Obsidian.
Engineered for decades of sustained thought.
A second brain is only as good as its durability. Every component is designed around offline longevity and rapid access.
Conflict-free local synchronization
Type on your desktop without an internet connection. Edit the same note on your phone. When connected, changes merge deterministically without duplicate files.
Zero Knowledge Crypto
Your cryptographic keys never leave your device. Notes are encrypted with AES-256-GCM before touching any sync relay.
Sub-millisecond Search
SQLite FTS5 full-text indexing directly inside your browser and local client. Search through 100,000 notes in 4ms.
Infinite Visual Thought Canvas
Switch from markdown editor to a spatial 2D whiteboard. Lay out PDFs, quotes, sketches, and connections in one unbounded space.
From fleeting impulse to synthesized doctrine.
Three stages designed to eliminate capture friction and turn isolated fragments into enduring systems.
Omni-Capture
Global hotkey invokes floating modal. Record voice memos, drop code snippets, or clip article quotes without losing your current window.
Associative Synthesis
Synapse detects implicit links between recent captures and historical notes. Connect related ideas with a single keystroke.
Active Production
Assemble structured essays, technical specifications, and research papers from your graph. Export to LaTeX, Markdown, or PDF.
Endorsed by deep practitioners.
Engineers and academics who outgrew conventional nested folders.
"The graph visualizer is not a gimmick here. It caught three overlapping research citations that saved me weeks of redundant lab experiments."
"Having my entire knowledge repository stored as raw markdown on my SSD gives me complete peace of mind. Synapse is lighting fast."
"My writing output doubled within three months. The bidirectional links make synthesizing complex book chapters completely effortless."
Build your external cognitive cortex.
Download the desktop application for macOS, Linux, and Windows. Local files forever free.