JSONPath Tester

A JSONPath tester evaluates a JSONPath expression against a JSON document and returns every value the expression selects, along with the exact path to each match. JSONPath is a query language for JSON, the way XPath is a query language for XML: you write a short path such as $.store.book[*].author and get back the list of matching values without writing any code. This tool parses your JSON, runs the expression, and shows both the results and the normalized path of each one.

The point of a tester is feedback. When a JSONPath expression returns nothing, or returns more than you expected, the problem is almost always a small syntax detail: a missing wildcard, the wrong bracket style, or a filter that compares a string to a number. Running the query live against real data, and seeing which nodes it touches, turns that guesswork into a two second check. It is the same reason developers keep a regex tester open next to their editor.

Everything runs in your browser. The JSON is parsed with the built-in JSON parser and the expression is evaluated by a small interpreter written in JavaScript, so nothing is uploaded, logged, or stored. That matters because JSONPath work usually happens against API responses and config files that carry tokens, IDs, or customer records, and this tool keeps that payload on your own machine and keeps working offline once the page has loaded.

JSONPath is a convention with several implementations rather than a single specification, and they disagree at the edges. Filter syntax is the least portable part, so an expression that works in one library may need adjusting in another. Recursive descent is the expensive operation: it walks every node in the document, so on a large file a query beginning with two dots is noticeably slower than an explicit path.

To try it as a JSONPath online evaluator, click Load Sample, replace the expression with $.store.book[?(@.price < 10)].title and click Evaluate. Values mode returns ["Sayings of the Century", "Moby Dick"] with the pane marked 2 results. Switch Output to Paths and click Evaluate again, and the same query returns $.store.book[0].title and $.store.book[2].title, which tells you the filter skipped the books at index 1 and 3. Change the expression to $..price and you get five numbers, because recursive descent also reaches the bicycle.