JSON Viewer & Formatter — Pretty Print, Tree, Search

Format and explore JSON in a fast collapsible tree. Search, copy paths, big files. No ads, no tracking, open source.

JSONDesk is a JSON viewer and JSON formatter that makes no network requests. No ads, no analytics, no tracking, no remote code, and the source is on GitHub. Open any JSON URL and it becomes a fast, collapsible JSON tree. Pretty print JSON from an API response, a config file or a webhook payload, format JSON you paste in, then find the one field you need. ⚡ FAST ON BIG FILES • 5 MB of minified JSON is ready in about half a second, and scrolling stays smooth with hundreds of thousands of rows. • Large files are parsed in slices with progress, so the tab never locks up. • Opens to the level you choose, with item and key counts on every folded node. 🔎 SEARCH, QUERY AND COPY • Search keys and values, with a match count and next / previous. • Type a JSONPath query like $.items[?(@.price > 10)].id and get a list of results, copied as a JSON array in one click. • Copy a value, a whole node as formatted JSON, or its path (data.items[3].id). • Switch between the tree and the raw text without losing your place. • Works as a JSON beautifier too: Copy formatted gives you pretty-printed JSON in one click. ✅ CORRECT, NOT APPROXIMATE • Big numbers are shown exactly as sent. 12345678901234567890 is never rounded. • Key order and duplicate keys are kept as written. • Invalid JSON shows the error with line and column, and the raw text with the spot marked. • XSSI prefixes like )]}' and JSONP wrappers are removed and noted. 🔒 PRIVATE BY DESIGN • Zero network requests. You can check: DevTools → Network shows only the page itself. • What you view stays in your tab and is never saved. JSONDesk only keeps your settings and a count of documents opened, on this device. • A paste and drop page for JSON that isn't in a tab, which works with no permissions at all. 🧰 ALSO • Compare two JSON documents: every changed, added and removed value, with its path. • JSON Lines / NDJSON open as a list of records. • Sort keys A→Z without changing what you copy. • Raw view with line numbers and a minimap. • Light and dark themes, and full keyboard control (press ? for the shortcuts). • Open .json files from your computer too. 📋 WHAT IT CAN DO, IN PLAIN WORDS • Shows JSON pages as a tree: when a website sends a page labelled as JSON, or a plain-text page that is valid JSON. Other pages are never read. • Relabels those pages before they load: Chrome freezes on large JSON pages, so JSONDesk changes their Content-Type header to plain text first. Only pages you open in a tab, never the requests a website makes itself. • Remembers your settings (theme, open level, sorting, plain-text pages) on this device. Chrome sums this up as "Read and change all your data on all websites", because that is the smallest permission that lets an extension see which pages are JSON. 🌍 Available in 51 languages. 💛 Free No account, no ads. JSONDesk is made by one independent developer and supported by optional tips on Ko-fi. JSONDesk is a JSON parser and viewer, not a JSON editor: it never changes or sends your data.