Development · Browser only
Huge JSON Viewer
Open large JSON files online with a streaming parser, Web Worker, and virtualized tree. Search keys or values without freezing your tab.
Your JSON file never leaves your device.
Your JSON file never leaves your device. Parsing and search run only in this browser tab.
Built for scale
Inspect structure, not a giant text blob.
The parser reads the selected file in chunks in a Web Worker and keeps a compact structural index with short previews. The original JSON text is never uploaded or held as one large browser string.
Search & navigate
Find matching keys or values, expand only the levels you need, and browse a tree that renders only the rows currently on screen.
Privacy
Your JSON file never leaves your device. There is no upload endpoint, account, storage, database, or server-side processing.
Limits
Very deeply nested JSON and files with an extremely large number of distinct nodes can still exceed a device's available memory. Clear the file when you are done to release the in-memory index.