Paste a JSON array, get a CSV file. Nested objects? Flattened with dot notation. Perfect for API responses that need to go into Excel.
JSON (JavaScript Object Notation) uses nested trees of objects and arrays. CSV (Comma-Separated Values) is a flat table format. Converting between them requires flattening nested structures into columns.
Dot-notation flattening: The nested object {"address": {"city": "NYC", "zip": "10001"}} becomes two CSV columns: address.city and address.zip. This is the standard approach used by MongoDB, pandas json_normalize(), and AWS Athena.
Limitations: Arrays of mixed types cannot be flattened deterministically. Highly nested structures (>5 levels deep) produce unwieldy column names. This converter handles the 95% use case: arrays of objects, which covers virtually all REST API responses.
See also: JSON Formatter · JSON Minifier · JSON → Code Generator