JSON Lens — Local JSON Formatter & Viewer

JSON Lens is a JSON formatter and viewer that runs entirely on your machine. Paste JSON (or open a .json file, or read from your clipboard) and get instant formatting, syntax highlighting, validation with exact line/column error locations, a collapsible tree view for nested documents, and full-text search with match navigation. Copy back formatted or minified with one click. Why local matters: A lot of us paste API responses, config files, and logs containing tokens and secrets into online formatters without thinking twice. JSON Lens exists so you never have to make that trade-off: there is no server, no analytics, no ads, and no account. The extension requests only two permissions — clipboard access (only when you press the Paste button) and local storage (to remember your input on a refresh). There is physically nowhere for your data to go. You can read the entire source to verify. Features: Paste, upload, or read-from-clipboard input; Format + validate with errors pinpointed to line and column; Collapsible tree view with expand-all / collapse-all; Syntax-highlighted text view; Search across the document with match navigation; One-click copy formatted/minified; Follows your OS light/dark theme; 100% local — zero network requests. Privacy: JSON Lens collects nothing, uploads nothing, and tracks nothing. All parsing, rendering, searching, and copying happen inside the tab's JavaScript engine. No account, no analytics, no ads. Full privacy policy at the URL below.