# Convert JSON to CSV - Flatten Nested JSON & JSON Lines (`tidybytetools/json-to-csv-flattener`) Actor

Flatten nested JSON or JSON Lines into CSV. $0.0001 per row converted. Failed files free. Works from Apify MCP and the API.

- **URL**: https://apify.com/tidybytetools/json-to-csv-flattener.md
- **Developed by:** [Tidy Byte Tools](https://apify.com/tidybytetools) (community)
- **Categories:** Developer tools, Automation
- **Security:** Limited permissions
- **Stats:** 2 total users, 1 monthly users, 0.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $0.10 / 1,000 row converteds

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## JSON to CSV Converter - Flatten Nested JSON & JSON Lines

Turn nested JSON or JSON Lines into a flat CSV table for Excel and Google Sheets. Pick how lists are handled. $0.0001 per row.

### Website and local versions

- **[Website](https://tidybytetools.github.io/)** — Tidy Byte Tools product page
- **[Free local CLI + MCP](https://github.com/tidybytetools/json-shaper-lite)** — `pip install json-shaper-lite` (runs on your computer)

### What it does

- Flattens nested objects: user.name, user.address.city.
- Reads JSON, JSON Lines and Apify dataset links.
- Three ways to handle lists.
- Saves a CSV file and also puts rows in the dataset (download as Excel).
- Columns stay in the order they first show up.

### Price

You pay **$0.0001** per row converted (One flat row saved. Failed files are free.) There is no start fee from us. Apify adds its normal small platform cost.
Set a max cost for the run and we stop there. We never charge for work we did not save.

### How to use

1. Add links or paste your data.
2. Click **Start**.
3. Get results in the **Output** tab, or download them as CSV, Excel or JSON.

### Input

- **JSON file links**: Links to .json or .jsonl files. An Apify dataset items link works too.
- **Or paste JSON**: Paste JSON or JSON Lines.
- **Column name separator**: user.name uses '.'
- **Lists**: How to put lists in cells.
- **CSV delimiter**: Use semicolon for Excel in many EU countries.

### Example input

This is also the default sample, so a first run works if you just click Start.

```json
{
  "jsonText": "[{\"id\":1,\"user\":{\"name\":\"Ann\",\"tags\":[\"a\",\"b\"]}},{\"id\":2,\"user\":{\"name\":\"Bo\"}}]",
  "separator": ".",
  "arrays": "join",
  "csvDelimiter": "comma"
}
```

### FAQ

**How do nested keys become columns?**
Objects are flattened with a separator. With `.`, `user.name` and `user.address.city` become column names.

**What happens to lists?**
You pick: join the values in one cell, turn them into a JSON string, or make extra rows. Use the option that fits your spreadsheet.

**Can I use JSON Lines or an Apify dataset?**
Yes. Paste JSON or JSON Lines, or give a link to a `.json` or `.jsonl` file. An Apify dataset items link works too.

**My Excel (EU) splits columns wrong.**
Set the CSV delimiter to semicolon. That is the usual setting in many EU countries.

**Do I pay for a file that fails?**
No. Failed files are free. You pay $0.0001 for each flat row we save.

**Is there a free related tool?**
`json-shaper-lite` is a free local tool that turns notes, CSV and Markdown tables *into* JSON. It is not a JSON-to-CSV flattener. You can find it on [GitHub](https://github.com/tidybytetools/json-shaper-lite).

### Good to know

- Files up to 50 MB each.
- Your data is only used for your run.
- Made by Tidy Byte Tools. Questions? Open an issue on this Actor's page.

### More tools from Tidy Byte Tools

These Actors work well together:

- [PDF Table Extractor](https://apify.com/tidybytetools/pdf-table-pull) — PDF tables to CSV, Excel and JSON. $0.003 per page with a table.
- [PDF, Word and Web Page to Markdown](https://apify.com/tidybytetools/doc-to-markdown) — Clean Markdown and RAG chunks. $0.003 per file.
- [HTML Table Extractor](https://apify.com/tidybytetools/html-table-extractor) — Web tables to CSV and JSON. $0.0005 per data row.
- [Broken Link Checker](https://apify.com/tidybytetools/broken-link-checker) — Check site and sitemap links. $0.001 per link.
- [Markdown Chunker for RAG](https://apify.com/tidybytetools/markdown-rag-chunker) — Split Markdown by headings. $0.0001 per chunk.
- [CSV and Excel Data Cleaner](https://apify.com/tidybytetools/csv-excel-data-cleaner) — Dedupe and fix dates, emails and phones. $0.0005 per clean row.
- [JSON to CSV Converter](https://apify.com/tidybytetools/json-to-csv-flattener) — Flatten nested JSON for spreadsheets. $0.0001 per row.
- [CSV Encoding Fixer and Splitter](https://apify.com/tidybytetools/csv-encoding-fixer-splitter) — Fix garbled letters like é and split big files. $0.01 per file.
- [Phone Number Validator](https://apify.com/tidybytetools/phone-number-validator-formatter) — Check and format numbers offline. $0.001 per number.
- [LLM Token Counter](https://apify.com/tidybytetools/llm-token-counter) — Offline token and cost estimates for GPT, Claude and Gemini. $0.0005 per unique text.

Free local tools (no Apify account needed): [pdf-table-pull-lite](https://github.com/tidybytetools/pdf-table-pull-lite), [doc2md-lite](https://github.com/tidybytetools/doc2md-lite), [link-check-lite](https://github.com/tidybytetools/link-check-lite), [md-chunk-lite](https://github.com/tidybytetools/md-chunk-lite), [json-shaper-lite](https://github.com/tidybytetools/json-shaper-lite).

Website: <https://tidybytetools.github.io>. All Actors: [apify.com/tidybytetools](https://apify.com/tidybytetools).

### Agent tip

Flatten nested JSON or JSON Lines into CSV. $0.0001 per row converted. Failed files free. Works from Apify MCP and the API.

# Actor input Schema

## `fileUrls` (type: `array`):

Links to .json or .jsonl files. An Apify dataset items link works too.

## `jsonText` (type: `string`):

Paste JSON or JSON Lines.

## `separator` (type: `string`):

Provide Column name separator for this run. Used as input for: Convert JSON to CSV.

## `arrays` (type: `string`):

How to put lists in cells.

## `csvDelimiter` (type: `string`):

Use semicolon for Excel in many EU countries.

## Actor input object example

```json
{
  "jsonText": "[{\"id\":1,\"user\":{\"name\":\"Ann\",\"tags\":[\"a\",\"b\"]}},{\"id\":2,\"user\":{\"name\":\"Bo\"}}]",
  "separator": ".",
  "arrays": "join",
  "csvDelimiter": "comma"
}
```

# Actor output Schema

## `results` (type: `string`):

No description

## `files` (type: `string`):

No description

## `summary` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "jsonText": "[{\"id\":1,\"user\":{\"name\":\"Ann\",\"tags\":[\"a\",\"b\"]}},{\"id\":2,\"user\":{\"name\":\"Bo\"}}]"
};

// Run the Actor and wait for it to finish
const run = await client.actor("tidybytetools/json-to-csv-flattener").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "jsonText": "[{\"id\":1,\"user\":{\"name\":\"Ann\",\"tags\":[\"a\",\"b\"]}},{\"id\":2,\"user\":{\"name\":\"Bo\"}}]" }

# Run the Actor and wait for it to finish
run = client.actor("tidybytetools/json-to-csv-flattener").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "jsonText": "[{\\"id\\":1,\\"user\\":{\\"name\\":\\"Ann\\",\\"tags\\":[\\"a\\",\\"b\\"]}},{\\"id\\":2,\\"user\\":{\\"name\\":\\"Bo\\"}}]"
}' |
apify call tidybytetools/json-to-csv-flattener --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,tidybytetools/json-to-csv-flattener"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/UE2aImaZeneX7fG8A/builds/RichntvwkIauBauaG/openapi.json