JSON Formatter & Viewer

JSON formatter and viewer for Chrome — auto pretty-print, parse & validate, tree & text views, syntax highlighting, search.

JSON Formatter & Viewer is a fast JSON formatter and JSON viewer for Chrome. Open any JSON URL and it instantly parses and pretty-prints the raw text into a clean, interactive viewer — no clicks, no configuration. You can also paste your own JSON to format, minify, or validate it, with invalid JSON flagged at the exact line and column. TWO WAYS TO READ YOUR DATA • Tree view — collapsible nodes with array/object item counts. Expand or collapse the whole document with one button, or drill in node by node. • Text view — pretty-printed JSON with line numbers, syntax highlighting, and click-to-fold blocks. BUILT FOR REAL-WORLD PAYLOADS • Handles large files — the text view renders only the lines on screen, so multi-megabyte documents scroll smoothly. The tree builds children lazily, opening instantly no matter how deep the data goes. • Keeps the real URL — rendering happens in place, so the address bar, reload, back/forward, copy-link and the DevTools Network panel all keep working normally. • Accurate folding — fold boundaries are computed from the parsed data, so brackets inside string values never break the structure. • Long strings stay tidy — very long string values are truncated with a click-to-expand marker. FIND THINGS FAST • Search across both views with a live match count and prev/next navigation (‹ ›, Enter / Shift+Enter). In text view every match is highlighted; in tree view the current match's ancestors expand and scroll into view. MADE COMFORTABLE • Dark mode — follows your system theme with an in-page toggle. • Font controls — choose from 11 font families, including monospace and system fonts, and adjust the size. Your choice is remembered across documents and sessions.• Clickable links — http/https string values become safe links; other protocols render as plain text. • Syntax highlighting — distinct colors for keys, strings, numbers, booleans, and null. AUTOMATIC DETECTION Activates on application/json (and *+json) responses, and on text/plain or unlabeled pages whose body parses as valid JSON. PASTE YOUR OWN JSON • Manual input / formatter — click the toolbar icon to open an input page where you can paste or type JSON, then Format it (opens the viewer), Minify, Copy, Clear, or load sample data. Invalid JSON is flagged with its exact line and column. ## What's new WHAT'S NEW IN 0.3.0 • Renders JSON in place — the viewer is drawn over the original page instead of opening an extension page, so the address bar keeps the real URL and reload, back/forward, copy-link and DevTools behave normally. • Refresh no longer loses data — reloading a JSON page re-renders it; the manual viewer keeps the formatted JSON across refreshes (cleared when the browser exits). • Fewer permissions — removed an unused permission. • No style clashes — the viewer's appearance stays isolated from the page's own styles.