What does this tool do?
Flatten deeply nested JSON into a single-level object with dot or bracket notation keys. Everything runs locally using JavaScript in your browser — nothing you paste or upload is ever sent to a server.
How to use this tool
- Paste your nested json into the left-hand box.
- Fill in the key notation field above the input.
- Click Flatten JSON.
- Copy the flattened json from the output box.
Frequently asked questions
What is JSON flattening used for?
Flattening turns nested objects and arrays into a single-level object, which makes it easier to load JSON into spreadsheets, CSV exports, or flat database tables.
How are arrays handled?
Array items become keys with their numeric index, e.g. tags.0 and tags.1 in dot notation, or tags[0] and tags[1] in bracket notation.
Can I reverse the process?
Yes, use the JSON Unflattener tool to rebuild the original nested structure from a flat object.