JSONPath Tester

JSONPath, in one sentence

JSONPath is a selector: you give it a path and it returns the nodes that path points to. It does not transform, compute or reshape anything. If you want to group, sum or rewrite data, that is a different tool.

JSONPath is not jq

This site has both, and they are deliberately different:

If your expression contains arithmetic, map, group_by or builds a new object, you want JSON Query. If it is a path with wildcards or a filter, this is the one.

The syntax worth knowing

$.store.book[0].title        first element, by index
$.store.book[*].title        every element
$..price                     every price, at any depth
$.users[?(@.active)]         elements where active is true
$.users[?(@.age > 18)].name  comparison inside a filter
$['weird key']               keys that are not valid identifiers

Two details that surprise people: $..x (recursive descent) is greedy and can return a lot, and filter expressions run against each element, so @ is the current node.

How filters stay safe

Filters like ?(@.active) are expressions, and a naive implementation evaluates them with Function, which turns a JSON field into a place to run code. This tool uses a restricted evaluator: the expression can read the data, and nothing else. That is why an expression that tries to call arbitrary methods fails instead of executing.

When nothing matches

Zero results is a valid answer, not an error, and it is usually one of three things: the path has a wrong case, the data is an object where you expected an array (or the reverse), or the filter uses a field that does not exist on that element. The tester keeps syntax errors and empty results separate, because they need different fixes.

Format the JSON first with JSON Formatter if you are not sure it is even valid.