JSONPath Tester - Free Online Tool | PivaBox

Test JSONPath expressions against JSON data with real-time result display

JSONPath Tester — Evaluate and Debug JSONPath Expressions Against JSON Data with Real-Time Results, Syntax Reference, and Sample Data

Paste or type your JSON data into the input area — the tool validates your JSON as you type and highlights syntax errors with specific line references. JSONPath is to JSON what XPath is to XML — a query language for navigating and extracting data from JSON documents. While json.parse() in code gives you the whole object, JSONPath lets you surgically extract exactly the data you need: $.store.book[*].title extracts all book titles from a bookstore JSON in a single expression, equivalent to data.store.book.map(b => b.title) in JavaScript. JSONPath is widely used in API testing, data transformation pipelines, configuration management, and no-code/low-code platforms.
Enter a JSONPath expression in the second input field. The tool supports the complete JSONPath syntax: dot notation ($.store.book) for direct child access, bracket notation ($['store']['book']) for keys with special characters, wildcard (*.price) to match any key, array slice ([0:3] for first three elements, [-3:] for last three), recursive descent ($..author to find all 'author' keys at any nesting depth), union selector ([0,2,4] for specific indices), filter expressions ([?(@.price < 10)] to filter by child values, supporting comparison operators == != < <= > >= and logical operators && ||), and the current node reference (@ within filter expressions).
As you type, the tool evaluates your expression against the JSON in real-time and displays the matched results. Successful matches appear as extracted JSON values (strings, numbers, objects, or arrays) with a match count — you can see exactly which parts of the data your expression selects. Syntax errors in the JSONPath expression are caught and reported with descriptive messages. A helpful sample JSON dataset is provided by default (a bookstore catalog with nested books, authors, and prices) so you can start experimenting immediately without pasting your own data. Use JSONPath for: extracting API response fields for assertions in Postman tests, filtering large configuration files, transforming data in ETL pipelines, and building dynamic form renderers. All evaluation runs locally using the jsonpath-plus library — your JSON data, which may contain API keys or business data, never leaves your browser.

Frequently Asked Questions

How does JSONPath compare to alternatives like jq, JMESPath, or JSON Pointer for querying JSON data?

Each JSON query language serves different needs and ecosystems. JSONPath (RFC 9535, standardized 2024) is the most widely implemented — supported in JavaScript, Java (Jayway JsonPath), Python (jsonpath-ng), .NET, and testing tools like Postman and Karate. It's the safe default choice for cross-platform JSON querying. jq is a full programming language for JSON transformation with its own unique syntax — far more powerful than JSONPath (supports variables, functions, arithmetic, string manipulation, conditionals) but requires installing the jq binary and learning a new language. Use jq for complex CLI data processing; use JSONPath for simpler extraction within application code. JMESPath (AWS's query language) is similar in expressiveness to JSONPath but uses function-call syntax (<code>sort_by(contents, &date)</code>) rather than bracket-filter syntax; it's the standard in AWS CLI and SDKs. JSON Pointer (RFC 6901) is the simplest — it only supports exact path access like <code>/store/book/0/title</code> with no wildcards or filters; used primarily in JSON Schema and JSON Patch. The PivaBox JSONPath Tester helps you learn and debug JSONPath expressions with instant feedback — all processing happens in your browser.

What are filter expressions in JSONPath and how do they work with nested objects and arrays?

Filter expressions are JSONPath's most powerful feature — they select array elements based on conditions evaluated against each element. The syntax is <code>[?(expression)]</code> where <code>@</code> refers to the current element being tested. Examples: <code>$.store.book[?(@.price < 10)]</code> — all books cheaper than

0; <code>$.store.book[?(@.category == 'fiction')]</code> — all fiction books; <code>$.store.book[?(@.price < 10 && @.category == 'fiction')]</code> — cheap fiction books (AND logic); <code>$.store.book[?(@.isbn)]</code> — books that have an ISBN field (truthy check, useful for finding optional fields). Filters can compare against: literals (strings in single quotes, numbers, booleans <code>true</code>/<code>false</code>, <code>null</code>), child properties of <code>@</code> using dot or bracket notation, and other filters (limited nesting). Common pitfalls: string comparisons are case-sensitive; <code>null</code> comparison requires <code>@.field == null</code>; regex matching is not part of standard JSONPath (some implementations add it as an extension). The PivaBox JSONPath Tester uses the jsonpath-plus library which supports the full RFC 9535 filter syntax.

Can I use JSONPath for modifying JSON data, or is it read-only like XPath for XML?

Standard JSONPath (RFC 9535) is a read-only query language — it selects and extracts data but does not modify it. This mirrors the original design philosophy: JSONPath locates nodes, and your application code decides what to do with them. However, several implementations add mutation capabilities as extensions: jsonpath-plus (the library used by this tool) supports a <code>JSONPath({path, json, callback})</code> mode where you pass a callback function that receives each matched value and can return a modified value. In practice, most JSON modification is done in application code: (1) Parse JSON into native objects, (2) Navigate to the target location (optionally using JSONPath to find it), (3) Mutate the object directly, (4) Serialize back to JSON. For declarative JSON transformation, consider jq (which is explicitly designed for transformation) or JSON Patch (RFC 6902) which defines a standardized format for describing JSON modifications as a sequence of operations (add, remove, replace, move, copy, test). The PivaBox JSONPath Tester focuses on the query/selection use case — all evaluation runs client-side in your browser.