Open, format, and explore JSON in a fast collapsible tree with instant search — even when the file is huge. Everything runs in your browser. Nothing is uploaded.
Open the JSON viewer → Paste or open a fileThe tree loads in chunks, so megabytes of JSON open instantly instead of freezing the page.
Search across every key and value and jump straight to the matches, deep in the structure.
All parsing happens locally in your browser. Your JSON is never sent to a server.
Beautify or minify with one click, with syntax highlighting and collapsible nodes.
Most online JSON tools were built for small snippets. Paste a few megabytes of API response or a large log export and they hang, crash the tab, or upload your data to a server you don't control. This one renders large documents incrementally and keeps everything on your machine, so you can actually read the file in front of you.
Paste JSON or open a .json file, expand and collapse the tree, search keys and values, and copy the result pretty-printed or minified. No account, no ads, no sign-up.
JSON viewer for large files · JSON to CSV converter · CSV to JSON converter · JSON escape / unescape · JSONPath tester · JSON diff · Text diff checker · JSON to TypeScript · JSON to YAML · JSON to XML · JSON flatten · JSON sort keys · NDJSON ⇄ JSON · JWT decoder · Unix timestamp converter · Base64 encode / decode · URL encode / decode · HTML entity encode / decode · SHA hash generator · UUID generator · Case converter · Regex tester · Word counter · Lorem Ipsum generator · Formatter / minifier
Guide: how to open a large JSON file · Guide: query JSON by path · Guide: validate JSON · Guide: fix JSON errors · Guide: what is a JWT? · Regex cheatsheet · JSONPath cheatsheet · What is Base64? · JSON vs XML
Is it free? Yes — the viewer, formatter, search, JSON→CSV converter, and JSONPath tester are all free. An optional one-time Pro adds in-viewer querying and CSV export.
Is my JSON uploaded anywhere? No. Everything runs in your browser; your data never leaves your device, and there's no tracking.
How large a file can it open? It renders the tree incrementally, so multi-megabyte files open without freezing — far past where most online formatters give up.
Do I need an account? No account, no sign-up.