What does it mean to Flatten JSON?

Flattening a JSON object means taking a hierarchical, multi-level data structure and collapsing it into a single level. This is essential when you need to export data from a NoSQL database (like MongoDB) or a complex API into a flat tabular format like CSV or Excel.

With our Online JSON Flattener, you can instantly convert any nested JSON into a flat CSV format. For example:

{
  "user": {
    "details": {
      "name": "Alex"
    }
  }
}

Becomes a flat object with a dot-notation key:

{ "user.details.name": "Alex" }

Ready to try? Just drag and drop your file above. It's fast, free, and operates entirely in your browser to guarantee privacy.