JSON Path Evaluator

What is JSON Path Evaluator?

JSON Path Evaluator tests JSONPath expressions against a JSON document and highlights matching values in real time. It supports the full JSONPath specification including recursive descent (..), wildcard (*), array slicing ([start:end:step]), filter expressions ([?(@.price < 10)]), and script expressions. The tool displays matched values alongside their full paths within the document structure.

API developers writing test assertions, data engineers building ETL extraction rules, and backend developers implementing dynamic JSON query features. The tool runs entirely in your browser — your data never leaves your device.

How to Use JSON Path Evaluator

1. Paste your JSON document into the left editor panel
2. Type a JSONPath expression in the query field — for example, $.store.book[*].author
3. View the matched values highlighted in the JSON document and listed in the results panel
4. Click on any result to see its full path within the document
5. Iterate on your expression using real-time feedback until it selects exactly the data you need

Common Use Cases

• Writing extraction queries for API test assertions in tools like Postman or REST Assured
• Developing data transformation rules for ETL pipelines that use JSONPath-based selection
• Debugging jq or JSONPath queries before embedding them in production code
• Extracting specific fields from complex nested API responses for logging or monitoring
• Building dynamic configuration selectors that target specific JSON nodes by path

Pro Tips

• Use the recursive descent operator .. to find keys at any depth — $.store..price finds all price fields regardless of nesting level
• Filter expressions like [?(@.price < 10)] evaluate against each array element — combine with && and || for complex conditions
• JSONPath implementations vary between languages — Python jsonpath-ng, JavaScript jsonpath-plus, and Java Jayway have subtle differences in filter syntax and edge case handling

Why Use This Tool?

• Privacy-first: All processing happens locally in your browser. No data is transmitted to any server.
• No installation required: Works in any modern browser on desktop or mobile.
• Completely free: No account, no credit card, no usage caps.
• Fast and reliable: Powered by modern Web APIs for near-instant results.

Related Concepts

Learn more about related topics: JSONPath RFC 9535, jq, XPath, JSON Pointer.

Frequently Asked Questions