Free JSON Tools for API Debugging

An API response is hard to debug when it will not parse, contains thousands of records or changes on every request. Start with the problem you need to solve, then use an example to check the result.

Choose a JSON tool Follow a guide

Choose the tool for your problem

Why will this JSON not parse?

Check syntax, locate an error and format the corrected document.

Open JSON Formatter Example: Find and fix JSON syntax errors

How do I extract just the records I need?

Select nested values or filter an array, then inspect their locations.

Open JSONPath Tester Example: Filter a nested API response with JSONPath

What actually changed in this response?

Compare records by ID and exclude selected timestamps or other volatile fields.

Open JSON Diff Example: Compare JSON arrays by ID Example: Compare responses while ignoring timestamps

What shape should this API response have?

Infer a starting schema, then review required fields and allowed value types.

Open JSON Schema Generator Example: Generate JSON Schema from an API response

A practical API debugging workflow

Validate the document. A JSONPath query or comparison needs valid JSON first. If the response is HTML or incomplete, check the request before editing the data.
Select the relevant records. Use JSONPath to remove unrelated sections from the investigation. Keep the full response when context matters.
Compare with explicit rules. Use record IDs only when array order has no meaning. Ignore a field only when its changes are irrelevant to your question.
Describe the expected shape. Generate a schema from representative samples, review it against the API contract and validate future responses in your own application.

Worked JSON guides

Each guide includes data you can paste into a tool, the output to expect and mistakes to avoid.

Find and fix JSON syntax errors

Repair quotes, commas and incomplete responses without changing their meaning.

Filter a nested API response with JSONPath

Extract matching records, read individual fields and find their original locations.

Compare JSON arrays by ID

Separate record changes from harmless changes in array order.

Compare responses while ignoring timestamps

Exclude specific volatile paths while keeping meaningful differences visible.

Generate JSON Schema from an API response

Understand inferred types, optional fields and the limits of a single sample.

Need a different output format?

After checking the data, use JSON to CSV for spreadsheet rows, JSON to TypeScript for starting type definitions or JSON to YAML for a YAML representation.

These tools help inspect and transform data. A successful syntax check does not establish that an API response follows your contract, and a schema inferred from one sample needs review.