JSON Tools

JSON won by being boring: no schemas to agree on up front, no whitespace rules to argue about, and a grammar small enough to fit on an index card. That simplicity is also where most of the pain in working with it comes from. A trailing comma, a single-quoted string, an unescaped newline inside a value — any of these produces a document that looks fine to a human and fails JSON.parse outright, usually with an error message that names a byte offset instead of the actual problem.

The tools in this category exist for the different stages of that problem. Formatter and Minifier are opposite ends of the same transform — indent for a human to read, strip for a wire payload — and neither changes the data, only its presentation. Validator and Parser both catch malformed input, but answer different questions: Validator checks conformance and reports where it broke, while Parser is for when you actually want the parsed structure back along with a plain-English explanation of what went wrong. Viewer and JSONPath Tester are for exploration — collapsing a large document into a navigable tree, or querying it directly instead of scrolling. Schema Validator moves up a level, checking not just that a document is valid JSON but that it matches a shape you've declared. Diff answers "what changed" between two versions with dot-notation paths instead of a wall of red and green text.

All of it runs on the browser's native JSON.parse/JSON.stringify, which means the same strictness you'd hit in production — no trailing commas, no comments, double-quoted keys only. That's deliberate: a formatter that's more lenient than the JSON your actual code will parse just moves the failure downstream. The one practical limit worth knowing is a 5 MB input cap on tools that hold the full parsed structure in memory at once, there to keep the tab responsive rather than to silently truncate your data.