JSON Viewer
Paste, format, validate and explore JSON with collapsible tree view and search
Paste JSON to validate it, pretty-print or minify it, and explore it as a collapsible tree. Search across keys and values to find what you need in large API responses or configuration files. More free security tools.
Malformed JSON is one of the most common causes of broken API integrations — a trailing comma, an unescaped quote, or a missing bracket will fail silently in many contexts and loudly in others. This viewer parses your input with the browser's native JSON parser and reports the exact error, so you can fix the real problem instead of guessing.
Once valid, the collapsible tree view lets you drill into deeply nested API responses or configuration files without scrolling through thousands of minified characters, and the search highlights matching keys and values across the whole structure. Pretty-printing and minifying are the same operation in reverse — re-serialising the parsed object with or without whitespace.
Need help building secure APIs that handle JSON payloads safely?
If you like this tool, Speak with OneFirewall