JSONPath Tester

Supported JSONPath syntax

• $ selects the root document.
• .key, ['key'], or ["key"] selects an object property.
• [0] selects an array item by its zero-based index.
• [*] or .* selects every value at the current level.
• ..key recursively finds a property with that name at any depth.

Segments can be chained. For example, $.store.books[*].author.name selects every author name inside the books array, while $..price finds every property named price anywhere in the document.

JSONPath query example

{
  "store": {
    "books": [
      {"title": "Practical APIs", "price": 18},
      {"title": "Reliable JSON", "price": 24}
    ]
  }
}

Running $.store.books[*].title returns two matches: $.store.books[0].title and $.store.books[1].title. Running $..price returns both numeric prices. A valid query with no matching path returns “no matches”; that is different from a syntax error.

Unsupported expressions and common errors

This focused tester does not execute filter predicates such as [?(@.price < 20)], array slices, unions, or script expressions. Unsupported input is rejected rather than interpreted approximately. That makes results predictable, but it also means an expression copied from a more complete JSONPath implementation may need to be simplified.

• Path must start with $: add the root marker before the first segment.
• Unexpected token: check brackets, quotes, and dots around the reported fragment.
• No matches: verify property spelling and remember that object keys are case-sensitive.
• Invalid JSON: validate or repair the document before evaluating its path.

When to test JSONPath

JSONPath is useful for preparing test assertions, extracting fields from API responses, configuring observability pipelines, mapping webhook payloads, and locating values in automation workflows. A tree view can help discover the structure first; then this tester confirms that the expression selects only the intended values. Input, expressions, and results remain in the current browser tab and are not uploaded to Cryonel.

Test expressions against representative payloads, including missing optional fields, empty arrays, and multiple matches. A path that works for one sample may return nothing when an upstream service omits a branch. Keeping these edge cases in fixtures makes later integration failures easier to diagnose.