JSONata Tester
Test JSONata expressions against your JSON in the browser using the official engine. Formatted results, parse/runtime error separation, and reusable examples.
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What is JSONata Tester?
JSONata Tester runs JSONata query expressions against your own JSON, entirely in the browser, using the official jsonata engine. Paste data, type an expression, and see the formatted result instantly - with syntax and runtime errors clearly separated and five reusable examples covering paths, filters, projections, and aggregations.
Key Benefits
- Learn JSONata faster with live evaluation and instant error feedback
- Behavior matches production because the official engine is embedded
- Reusable examples double as a mini cheat sheet for common patterns
- Formatted results with one-click copy for docs and issue reports
- Completely private - data is evaluated locally, never uploaded
Common Use Cases
- •Debugging Node-RED or integration-platform mappings before deploying them
- •Prototyping JSON-to-JSON transformation expressions for API workflows
- •Learning JSONata syntax with immediate feedback on mistakes
- •Verifying that an expression handles edge cases in your real payloads
How to Test a JSONata Expression
- Paste your JSON: Drop your JSON document into the data box, or start from one of the built-in examples.
- Write the query: Type a JSONata expression - paths, filters, projections, and function calls all evaluate live as you type.
- Read and copy the result: Inspect the formatted result or the clearly labeled syntax/runtime error, then copy the output with one click.
Key Features
- Runs the official JSONata engine with the full built-in function library
- Evaluates live as you edit the query or the JSON data
- Separates syntax errors from runtime errors so you know what to fix
- Five reusable examples: paths, filters, projections, aggregations, and string helpers
- Formatted JSON results with one-click copy
- 100% in-browser - no upload, no account, no server