MyAITools
Transformer

JSON Flatten

JSON Flatten is a free online transformer that helps you flatten a nested JSON document to a single-level object with dot, underscore or bracket paths. JSON Flatten uses 2 input fields, returns 2 output values, and runs in your browser on the device.

Key facts

Inputs
2 fields: JSON and Separator
Outputs
2 values: Flat and Keys
Runtime
your browser on the device
Mode
Transformer
Privacy
Files and text stay in the browser session.
Cost
$0, no account required

How to use JSON Flatten

  1. 1

    Paste or fill in the input

    Enter your text or values into the input fields on the page.

  2. 2

    Run the utility

    Click Compute to run the utility in your browser and review the result.

  3. 3

    Copy the output

    Copy the output value you need from the result panel.

JSON Flatten details

First, enter JSON in JSON Flatten. Next, review Flat and Keys. Additionally, JSON Flatten uses 2 input fields and 2 output blocks so the result is easy to scan and copy.

Paste a nested JSON object or array and produce a single-level (flat) object where each leaf value is keyed by its full path. Choose between dot-notation (`a.b.0`), underscore (`a_b_0`) or array-bracket (`a.b[0]`) styles. Useful for spreadsheets, env-var generation or quick diffs across structurally similar payloads. Runs entirely in your browser; free, online, no upload.

Common searches

  • json flatten
  • flatten json
  • json to flat
  • json dot notation
  • json one level
  • flatten nested json

Related tools

Tools that work with the same formats — most users open one of these next.

Text & EncodingTransformer

JSON Unflatten

Expand a flat dot/bracket-keyed object back into nested JSON — numeric keys become array indices.

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Text & EncodingTransformer

JSON Sort Keys

Sort the keys of a JSON object alphabetically — recursively, case-insensitively, or with numeric awareness.

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Text & EncodingFormatter

JSON Formatter

Pretty-print or minify any JSON document — validates structure and reports parse errors with position.

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Text & EncodingGenerator

JSON Patch Generator

Generate an RFC 6902 JSON Patch describing the changes needed to turn one JSON document into another.

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Text & EncodingGenerator

JSON Schema Generator

Infer a JSON Schema (Draft-07) from any JSON document — nested objects and array element types are inferred recursively.

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Text & EncodingQuery

JSONPath Finder

Query a JSON document with a JSONPath expression — supports $, ., [n], [*], ..key and [?(@.field op value)] filters.

Try it →

Frequently asked

What is JSON Flatten?

JSON Flatten is a free online transformer that helps you flatten a nested JSON document to a single-level object with dot, underscore or bracket paths. JSON Flatten uses 2 input fields, returns 2 output values, and runs in your browser on the device.

What inputs and outputs does JSON Flatten use?

JSON Flatten uses 2 input fields: JSON and Separator. JSON Flatten returns 2 output values: Flat and Keys.

Do my files and data stay private?

Yes. JSON Flatten runs entirely in your browser using your device's CPU. Files and text are never uploaded to our servers, so your data stays private.

How do I use JSON Flatten?

Open JSON Flatten, paste or fill in the input fields, and the result updates instantly. JSON Flatten runs in your browser with no upload and no waiting.

Which browsers does JSON Flatten support?

Any modern browser works in Chrome, Firefox, Safari, and Edge on desktop and mobile. JSON Flatten uses standard web APIs and does not require any plugin, extension, or sign-up.