# JSON to CSV converter: run it free, or from your agent

Converts a JSON array to CSV in the browser, flattening nested keys into dotted columns. Preview, copy or download.

## Prompt

Use looot to pull [data, such as dentists in Lyon from Google Maps] and save it as CSV. 1. Set up https://looot.ai/skill.md. 2. Search the catalog for an endpoint that returns this data and check its price before you call. 3. Run it. 4. Flatten the JSON rows to CSV with dotted column names, join list fields with semicolons and save results.csv. 5. Return the row count and the cost.

## What it needs

A JSON array of objects, or an object that holds one

## What comes back

- CSV text
- column names from flattened keys
- row and column count
- table preview

## Endpoints and providers

None. The tool on the web page runs in the browser and calls no endpoint.

## What it costs

Nothing. The tool on the web page runs in the visitor's browser: no account, no API call and no limit per hour. The prompt above runs the same job from your own looot account with current data, billed per call.

## API answer to sheet

Turn a JSON response into a table you can sort and filter in Excel or Sheets.

## Check a payload

See every key every row uses, including the ones only some rows have.

## Quick import

Prepare a CSV for a CRM or database import without writing a script.

## Agent output

Paste what your agent returned and hand the CSV to a teammate.

## How do I convert JSON to CSV?

Paste the JSON in the box. A top-level array becomes the rows. If the JSON is an object, the first array of objects inside it, such as results or data, becomes the rows. The CSV appears below as you type.

## How are nested objects handled?

They are flattened into dotted column names. An address object with a city field becomes an address.city column.

## What happens to arrays inside a row?

Pick one of three modes: join plain values into one cell with semicolons, give each item its own column such as tags.0 and tags.1, or keep the array as JSON text in one cell.

## What if rows have different keys?

The CSV gets every key that appears in any row, in the order they first appear. Rows without a key get an empty cell.

## Can I open the CSV in Excel?

Yes. Download the .csv and open it. For locales that use a comma as the decimal mark, pick the semicolon delimiter. Turn on spreadsheet safe to stop cells that start with = from running as formulas.

## How big a file can it convert?

Up to 50,000 rows and 20 MB per file, in the browser. For larger exports a script or a command line tool is faster.

## Are large numbers kept exactly?

Yes. Numbers are copied as written, so a 19 digit id does not get rounded the way JSON.parse would round it.

## Is my data uploaded?

No. The conversion runs on this page and files are read locally.

## Related tools

- /free-tools/json-formatter
- /free-tools/regex-tester
- /free-tools/curl-to-fetch-converter

## Last reviewed

2026-10-14.