JSON Viewer & Formatter — PureJSON by Antoni0

PureJSON turns raw JSON pages into a clean, fast, collapsible tree — and it never sends your data anywhere.

FIREFOX SETUP (one time): Firefox has its own built-in JSON viewer. To let PureJSON format JSON pages, open about:config and set devtools.jsonview.enabled to false. A welcome page with these steps opens right after install. The popup scratchpad works without this step.

Built as a privacy-first JSON formatter: no analytics, no ads, no tracking, no remote code. Everything runs locally in your browser.

FREE FEATURES
• Automatic formatting of JSON pages and API responses
• Collapsible tree with syntax highlighting
• Tree, Pretty and Raw views
• Click any key to copy its path (e.g. data.users[0].email) or copy any value
• Expand all / Collapse all
• Dark and light themes
• Big IDs stay exact: numbers longer than 16 digits (Twitter/X, Discord, Telegram, banking IDs) are shown exactly as the API sent them
• Opens 20 MB+ files without freezing the tab
• Clear error messages with line and column for invalid JSON
• Popup scratchpad: paste any JSON to format, minify or view as a tree
• No usage limits: free features stay free forever

PRO FEATURES (one-time payment, lifetime — no subscription)
• Table view — any array becomes a sortable, filterable spreadsheet right in the browser
• Export to CSV / Excel in one click — nested objects are flattened into clean columns, exported exactly as you sorted and filtered them. Includes a semicolon CSV for European Excel and TSV.
• TypeScript generator — turn any response into ready-to-paste interfaces
• Deep search & filter — find any key or value instantly; the tree filters as you type

Pro is sold through Gumroad. Free features have no limits and no countdown — they stay free.

PRIVACY
PureJSON does not collect any data. The only network request it can make is a license check to Gumroad when you activate a Pro key. Your JSON never leaves your browser.

SECURITY
JSON content is always rendered as plain text, so malicious HTML or scripts inside a payload can never run. CSV exports are protected against spreadsheet formula injection.