Flatten a List

Flatten a nested list with this easy online tool. Supports JSON input, removes duplicates, trims quotes, and sorts output. Import files, export results, and view live changes instantly.

Paste your input above or import a file below.
No file chosen
Supported file types: .txt, .json, .csv, .tsv, .log, .md, .ini, .yaml, .yml, .html, .htm, .xml, .css
Total items: 0
Options
Remove surrounding quotes
Sort items alphabetically
Remove duplicates

How to Use:

  1. Paste your nested list in JSON format into the input box or use the file import feature.
  2. Adjust Options like removing duplicates, trimming quotes, or sorting alphabetically.
  3. Click Flatten or start typing to preview output live.
  4. Use the Copy Output or Export to File buttons to save your results.
  5. Click Clear All to reset everything.

What Flatten a List Tool Can Do:

This tool takes any deeply nested list (like a JSON array) and converts it into a flat, single-level list. You can choose to remove surrounding quotes, sort the output, and filter out duplicate entries. It processes input instantly, gives live feedback, and works completely in the browser.

Example:

Before:

[[1, 2], [3, [4, 5]], 6]

After:

1
2
3
4
5
6

Common Use Cases:

Ideal for processing scraped data, normalizing nested arrays, cleaning JSON payloads, or preparing data for spreadsheets and analysis. It’s especially useful for developers, data analysts, and anyone working with structured text or code output.

Useful Tools & Suggestions:

If you’re flattening a list, Join List Items helps you collapse everything into a single string perfect when you’re prepping for export or compact display. Then, if your entries had nested formatting or symbols, Trim List Items clears out any leftovers to keep the result clean. It’s a quick way to simplify complex lists and get everything into a neat, linear format.

Related Tools