JSONPath, JMESPath and jq: one input, checked results

Use the query language your host application supports. A query copied from jq cannot be pasted unchanged into JSONPath, and a successful browser test does not establish that a different library supports the same extensions.

Run the same selection

Download books.json. Open the JSONPath tester, paste this input, then select titles priced below 10:

{"books":[{"title":"A","price":8},{"title":"B","price":12},{"title":"C","price":9}]}

JSONPath expression:

$.books[?(@.price < 10)].title

Expected selected values in the tester:

["A","C"]

Equivalent standard JMESPath expression (the backticks delimit a JSON numeric literal):

books[?price < `10`].title

Equivalent jq command, with brackets collecting values into one array:

jq '[.books[] | select(.price < 10) | .title]' books.json

All three yield ["A", "C"] as values for this input. Without jq’s outer brackets, the command emits two separate JSON strings. That difference matters if a downstream process expects one document rather than a stream of values.

Selection and transformation are different tasks

JSONPath selects nodes. To rename fields, construct objects with a language that supports that operation. For example, JMESPath:

books[?price < `10`].{name: title, cost: price}

And jq:

jq '[.books[] | select(.price < 10) | {name: .title, cost: .price}]' books.json

Expected output:

[{"name":"A","cost":8},{"name":"C","cost":9}]

JMESPath defines functions such as sort_by, length and contains. Their input type requirements are checked during evaluation; a syntactically valid query can still fail on incompatible data. Do not assume a function from jq also exists in JMESPath.

Test empty and missing data too

Change the price threshold to zero: the collected output should be []. Remove the books property and repeat: implementations differ in whether missing paths become null, no matches or an error once another operation is applied. Decide which result your integration accepts rather than letting an empty report silently look like success.

An individual JSON Pointer, such as /books/0/title, identifies one location. It is not a JSONPath filter. Schema validation error paths often use Pointer conventions, so check the producer’s format before interpreting them.

Choose a place to run the query

JSONPath is useful when the answer already exists in the input and your application accepts its dialect. JMESPath is used by the AWS CLI --query option and can construct result objects. jq is convenient for shell transformations and can work with streams, although its default document parsing still materializes input.

JSONCraft provides JSONPath and a tree viewer; it does not claim to run JMESPath or jq in the browser. For larger exports, see the streaming guide.

References: JSONPath RFC 9535, JSONPath Plus documentation, JMESPath specification, jq manual.