Convert JSON to CSV - Flatten Nested JSON & JSON Lines

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 — Tidy Byte Tools product page
• Free local CLI + MCP — 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.

{
  "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.

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 — PDF tables to CSV, Excel and JSON. $0.003 per page with a table.
• PDF, Word and Web Page to Markdown — Clean Markdown and RAG chunks. $0.003 per file.
• HTML Table Extractor — Web tables to CSV and JSON. $0.0005 per data row.
• Broken Link Checker — Check site and sitemap links. $0.001 per link.
• Markdown Chunker for RAG — Split Markdown by headings. $0.0001 per chunk.
• CSV and Excel Data Cleaner — Dedupe and fix dates, emails and phones. $0.0005 per clean row.
• JSON to CSV Converter — Flatten nested JSON for spreadsheets. $0.0001 per row.
• CSV Encoding Fixer and Splitter — Fix garbled letters like é and split big files. $0.01 per file.
• Phone Number Validator — Check and format numbers offline. $0.001 per number.
• 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, doc2md-lite, link-check-lite, md-chunk-lite, json-shaper-lite.

Website: https://tidybytetools.github.io. All Actors: 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.