JSON Viewer & Formatter — Big Files, Tree & Search

Open, format & explore huge JSON fast. Collapsible tree, instant search, highlighting. 100% local & private.

Tired of your browser or DevTools choking on a big JSON response? This is a fast, no-nonsense JSON viewer built to stay smooth on files that make other tools freeze. • Format & beautify JSON — click the toolbar icon on a page showing raw JSON, or paste it / open a .json file. • Built for big files — the tree loads in chunks to keep large documents manageable. • Instant search across keys and values, jumping straight to matches. • Syntax highlighting by type, expand/collapse, and one-click copy of pretty or minified JSON. • 100% local & private — your JSON never leaves your browser. No accounts, no servers, no tracking. The extension reads a page only when you click its icon. No clutter, no ads, no sign-up. Open your JSON and read it. Number safety: numbers that would change when copied are rejected before formatting. Arbitrary-precision JSON numbers are not supported. Version 0.1.1 also fixes copying the JSON value null and prevents a failed import from copying the previous document.