What JSON flattening is
Turn nested values into one-level path and value pairs
JSON flattening replaces object and array nesting with descriptive key paths. A nested value such as a user's city becomes user.address.city oruser[address][city], making the structure easier to pass into tools that expect one level of keys.
Common analytics workflows
Prepare event and API data for column-oriented systems
Analytics pipelines often receive nested event payloads but store dimensions and measures as flat fields. Flattening exposes nested attributes as predictable keys while retaining array indexes and original leaf values.
- Normalize API payloads before warehouse ingestion
- Expose nested event dimensions for analysis
- Prepare fixtures for ETL and mapping rules
- Inspect generated paths before defining columns
- Compare field coverage across sample events
- Create readable one-level debugging snapshots
Spreadsheet preparation
Make nested field names easier to map into columns
Flattened keys provide a clear inventory of possible column names before a spreadsheet import. When your source is an array of records that is already tabular, use JSON to CSV instead; the flattener is designed for inspecting and transforming nested structure.
Logging and telemetry
Create searchable paths for structured event details
Dot-separated paths are common in log processors, telemetry pipelines, and dashboards. Indexed array paths make each observed position explicit, while empty containers remain visible instead of disappearing from the output.
Configuration management
Review nested settings as explicit key paths
Flattening can help inventory configuration fields, prepare environment-variable mappings, and compare settings across systems that use path-based keys. UtilityDock preserves booleans, numbers, strings, nulls, empty objects, and empty arrays as JSON values.
Examples
Choose the path style your workflow expects
| Style | Flattened key |
|---|---|
| Nested input | {"user":{"address":{"city":"London"}}} |
| Dot notation | user.address.city |
| Bracket notation | user[address][city] |
| Indexed array | events[0][type] |
Data Toolkit
Continue with related UtilityDock data workflows
FAQ
Questions about flattening JSON
Does UtilityDock upload or store my JSON?
No. Your files never leave your computer. Validation, flattening, preview, copying, and download creation all happen locally inside your browser.
How are nested objects flattened?
Each object key becomes a path segment. Dot notation produces paths such as user.address.city, while bracket notation produces user[address][city].
How are JSON arrays handled?
Array positions become indexed path segments. Dot notation uses paths such as events.0.type, and bracket notation uses events[0][type]. Array order is preserved.
What happens to empty objects and arrays?
Empty objects and arrays are retained as values at their flattened path, so the output does not silently discard them.
What happens when a source key contains a dot or bracket?
UtilityDock backslash-escapes path separators that already exist inside source keys. This keeps generated paths distinct.
Can this tool reverse flattened JSON?
Use JSON Unflattener to reconstruct nested objects and indexed arrays from this tool's dot or bracket path output.