JSON & YAML Viewer

Collapsible tree view for JSON, YAML and XML in the browser. Fast on multi-million-line files; supports JSONC and light/dark themes.

JSON & YAML Viewer turns JSON, YAML and XML responses into a fast, collapsible tree, right in the tab. • Opens automatically by response MIME type, by file extension on plain-text hosts such as raw.githubusercontent.com, and for plain-text API responses that contain JSON. • Click any node to expand or collapse it; Alt+click toggles a whole subtree; Expand all / Collapse all. • Virtualized rendering: documents with millions of lines open in a fraction of a second and scroll smoothly. • JSON: big integers beyond 2^53 are shown exactly as sent; JSONC comments and trailing commas are accepted. • YAML: multi-document streams in block style. • XML: RSS, Atom, SOAP and other XML types. XHTML and SVG pages are left to the browser. • Raw view shows the original text. • Theme: follow the system, or force light or dark. Privacy: everything runs locally in your browser. The extension sends no network requests, collects no data and has no analytics. The only thing it stores is your theme choice.