JSON Graph Visualizer

A JSON graph visualizer turns a JSON document into a node-and-edge diagram: every object, array, and value becomes a node, and every parent-child relationship becomes an edge connecting them. That makes deeply nested structures — API responses, config files, database exports — far easier to scan than a wall of indented text, especially when you're hunting for where a specific field lives inside a large document.

Most existing JSON-to-graph tools render each node as a DOM element, which works fine for small payloads but falls over as the document grows — a few thousand nodes is enough to make some tools stutter, and tens of thousands can freeze the tab entirely. This visualizer renders directly to a <canvas> instead of the DOM, and only draws the nodes and edges currently inside your viewport (a spatial-index-backed culling pass), so pan and zoom stay smooth whether you're looking at a 20-node config or a 100,000+ node dump.

Everything happens client-side in your browser — your JSON is never uploaded anywhere.

1. Paste or type your JSON — into the input box, or click "Upload File" to load a .json file from disk.
2. Click Visualize — the JSON is parsed and laid out as a hierarchical node graph beneath the input.
3. Pan and zoom — drag anywhere on the canvas to pan, and scroll to zoom in or out. The visible node/edge count updates live below the canvas.
4. Click Fit to Screen — to re-center and re-scale the whole graph back into view after panning or zooming around.
5. Try Load Large Sample — to generate a synthetic ~120,000-node JSON document and see the huge-file handling in action.

• Canvas rendering with viewport culling — only nodes and edges inside the current view are drawn each frame, so render cost stays proportional to what's on screen, not the total document size.
• Handles huge files — a wide-and-shallow dataset with 100,000+ nodes stays smooth to pan and zoom, well past the point where DOM-based graph tools stop responding.
• Instant layout — an O(n) iterative layered layout (no physics simulation) positions every node in a single fast pass, even at large scale.
• Paste or upload — bring JSON in via textarea or file upload, with friendly error messages for invalid JSON instead of a crash.
• Live visible-node count — see exactly how many nodes and edges are currently rendered as you pan and zoom.
• 100% client-side — your JSON is parsed and rendered entirely in your browser. Nothing is uploaded, stored, or logged.

• Exploring API responses — quickly see the shape of a nested API payload without scrolling through indented text.
• Debugging config files — spot where a specific key lives inside a large, deeply nested configuration object.
• Reviewing data exports — visually scan large database or log exports (JSON dumps) that would be impractical to read line by line.
• Understanding unfamiliar JSON — get an at-a-glance structural overview of a JSON document you didn't write yourself.