JSONPath Evaluator
Evaluate an implemented JSONPath expression against local JSON and return the match as JSON. Unsupported syntax or no match returns an error.
About this jsonpath evaluator
Evaluate an implemented JSONPath expression against local JSON and return the match as JSON. Unsupported syntax or no match returns an error Transforms and validates developer data structures locally, preventing confidential payload exposure during data wrangling.
Syntax parsing & data transformation logic
Parse strict JSON and the complete supported property/index/bracket-key/[*] path, traverse the value, and serialize a match as JSON. Missing values and unsupported or trailing syntax return errors.
Worked conversion & output example
Scenario: Select one dotted JSON member with the bounded path evaluator.
Sample input:
Processing: Parse the first field as strict JSON, use the second field's dotted path, and serialize the selected result as JSON. Filter expressions are unsupported.
Illustrative output:
Syntax constraints & input size limits
This is a limited selector, not complete JSONPath. It accepts property access, numeric indexes, quoted bracket keys and [*]. Filters, recursive descent, slices and predicates are rejected instead of silently ignored.
Data conversions and formatting in JSONPath Evaluator reflect standard structured syntax. Verify parsed outputs against your target runtime before deployment.
Local client execution boundary
Data parsing and transformations in JSONPath Evaluator execute in the local browser tab without remote data transmission.
Data format specifications & language standards
Data interchange formats and language grammar specifications:
- RFC 8259 (The JavaScript Object Notation Data Interchange Format)
- ECMA-404 (The JSON Data Interchange Standard)
JSONPath Evaluator verification · Audit standards
How to use it
- Paste valid JSON and enter a supported property, index, quoted-key or [*] path.
- Parse the entire path and walk the JSON value; reject any unsupported path syntax.
- Read the selected value as JSON; a missing path returns an error.
Frequently asked questions
How does JSONPath Evaluator process data and path?+
It first parses primary input with strict interchange JSON handling, then passes the secondary JSONPath to evaluatePath. An undefined result throws `JSONPath did not match a value.` instead of returning a guessed value.
What does a dotted JSONPath selection return?+
For `{"user":{"name":"Ada"}}` with `$.user.name`, the output is the JSON string `"Ada"`. The path selects that dotted member; a path that finds no value returns an explicit error.
What inputs and output format are used?+
The page accepts JSON and a path, and serializes a matched value as JSON. Malformed JSON, missing values and unsupported or trailing path syntax return errors; the parser does not silently run a valid prefix.
What JSONPath functionality is not claimed?+
The evaluator implements its own bounded evaluatePath subset, not the entire JSONPath language. It does not establish compatibility with every filter, script expression, recursive descent, or external JSONPath engine.