Plain JSON — Fast Viewer, No Tracking

Fast collapsible JSON viewer and formatter built for large payloads. No account, no cloud, no telemetry, zero network requests.

Open a JSON endpoint in Chrome and you usually get one of two bad outcomes: an unreadable wall of text, or a viewer that locks the tab the moment the response is actually big. Plain JSON fixes both. It renders any JSON document as a collapsible, colour- coded tree the instant you open it — and it stays responsive on the payloads that matter, because it only ever puts the rows you can see into the page. WHY INSTALL IT • It does not choke on real data. Most viewers create one DOM node per value, which is why a large response freezes the tab. Plain JSON renders only the rows inside the viewport, builds child nodes the first time you expand them, and splits containers over 2,000 entries into [0 … 999] groups. A 50,000-item array stays navigable instead of becoming a wall. • It has the small things you reach for every day. Copy a JSONPath like data.items[3].name straight from the row. Search keys and values — including inside branches you have not expanded. Flip to the raw text in one click. Download the original file, which matters because the extension replaces the document, so the browser's own "Save page as" would otherwise save the rendered view instead of the JSON you came for. • It does not watch you. Plain JSON makes zero network requests. There is no analytics, no telemetry, no advertising, no affiliate code, and no third-party library anywhere in it. Your JSON is parsed in the tab and never leaves it. Your preferences are stored on your device only. This is not a promise in a policy document — an automated check fails the build if any URL appears in the source outside a two-entry allowlist. • It gets out of your way. Auto, light and dark themes. A font picker that lists only the faces actually installed on your machine, so every option visibly changes something. 21 interface languages. ALSO INCLUDED: A FORMATTER Click the extension icon to open a standalone paste-and-format tool. Paste JSON or drop a .json file, then format with 2-space indent or minify. Invalid input is reported with the exact line and column, and the last good tree stays on screen while you fix it. ABOUT THE PERMISSION JSON can be served from any URL, so the extension has to be allowed to look at any page in order to notice a JSON one. On a page that is not JSON it performs a single content-type check and stops — it does not read page content, does not touch the page, and does not inject anything. Combined with making no network requests at all, nothing from your browsing can leave your machine. Open source, so every claim above can be checked by reading the code.