JSON Unflattener

Free online JSON unflattener: restore a flat single-level JSON back into a nested structure. Ideal for reconstructing config data or API responses. Custom delimiter support, real-time conversion.

(default: dot)
Nested Result
{
  "user": {
    "name": "John",
    "age": 30,
    "address": {
      "city": "New York",
      "zip": "10001"
    }
  }
}
๐Ÿ’ก Tip: Unflattening example: {"user.name": "John"} โ†’ {"user": {"name": "John"}}. Useful for restoring config data processed by flattening tools, database key-value pairs, or any scenario requiring nested structure recovery.

What is Json Unflattener?

Convert between CSV, JSON, YAML, and other data formats. Shuffle lists, deduplicate entries, and reshape your data without writing a single line of code. It all runs in your browser, so sensitive datasets never leave your machine. Paste, convert, copy โ€” done.

โ–ถUse Cases5 scenarios
  • โ—†Switching between CSV, JSON, and other formats
  • โ—†Sorting lists and removing duplicates
  • โ—†Quick stats on your datasets
  • โ—†Processing bulk data without scripts
  • โ—†Cleaning messy data before importing it
โ–ถHow to Use6 steps
  1. 1Open the Json Unflattener โ€” no signup, no login.
  2. 2Paste your input or drag and drop a file.
  3. 3Hit Process or Generate and see results instantly.
  4. 4Preview the output and click Copy to grab it.
  5. 5๐Ÿ’ก Pro Tip: Check the FAQ below for power-user tricks.
  6. 6๐Ÿ“Œ Bookmark this page โ€” you will want to come back.
โ–ถFeatures8 features
  • โœ“Completely free
  • โœ“No account needed
  • โœ“Runs in your browser
  • โœ“Many formats supported
  • โœ“Instant processing
  • โœ“Copy with one click
  • โœ“Your data stays private
  • โœ“Works on any device
โ–ถFAQ7 questions
What is Json Unflattener?

An online data processing tool. Input: the raw data or content you need to process. Output: the processed result with one-click copy and download. Used for quick processing tasks in development, work, and study. Everything runs locally in your browser โ€” no data is uploaded.

What formats can I convert between?

CSV, JSON, XML, YAML, TOML, and more. If it is a structured data format, we probably support it.

How large a file can I use?

Up to about 10 MB runs smoothly. Bigger files might work but could slow things down a bit.

Does my data go to a server?

Never. Everything stays in your browser.

How fast is it?

Instant for typical files. Large datasets take a couple seconds at most.

Will I lose data during conversion?

Not between compatible formats. If something cannot map cleanly, we will let you know.

Can I use this on my phone?

Sure. Paste data, import files โ€” works fine on mobile too.