Key Takeaways
- The free converter turns CSV into JSON and JSON back into CSV, in both directions, with no upload.
- You can produce an array of objects, an array of arrays or newline-delimited JSON, and flatten nested keys into dotted columns.
- Files are parsed in a background worker in your browser, so nothing leaves your device.
- For repeatable conversion inside a spreadsheet, Flookup Data Wrangler adds cleaning and matching next to your data.
Introduction
Your analytics tool expects JSON. Your export gives you CSV.
Rewriting the file by hand is slow and easy to get wrong.
The free CSV and JSON converter moves data between the two formats in a click, in either direction, without sending a byte to a server. Open the CSV and JSON converter.
What the Converter Does
Feed it a file and it reads the structure, then writes the other format in the shape you choose:
- Flattening: nested JSON keys collapse into dotted column names such as location.city.
- CSV to JSON: header names become keys and each row becomes a record.
- JSON to CSV: keys become columns and each record becomes a row.
- Delimiter control: comma, tab, semicolon or pipe, on the way in and the way out.
You can also paste content straight into the tool instead of loading a file.
Choosing a JSON Shape
There is no single right JSON layout, so the tool offers three:
- Array of objects: every row becomes an object keyed by the header, the most common shape for APIs and document stores.
- Array of arrays: values only, with the header kept separate, which suits tools that read a schema first.
- Newline-delimited JSON: one object per line, the format that streaming and bulk import tools expect.
Pretty-printing adds indentation for reading and review, while compact output saves space for machines.
A Worked Example
Suppose your export looks like this:
| id | name | city |
|---|---|---|
| 1 | Alice | Nairobi |
| 2 | Bob | Kampala |
As an array of objects, the converter writes:
[
{ "id": "1", "name": "Alice", "city": "Nairobi" },
{ "id": "2", "name": "Bob", "city": "Kampala" }
]Switch the direction and the same JSON becomes the CSV above, with the keys on the first row and one record per line.
Privacy First
The file is parsed in a background worker in your browser.
Nothing is uploaded, stored or logged, so you can convert customer exports, pricing tables and internal records without a second thought.
How to Use It
- Choose the direction, CSV to JSON or JSON to CSV.
- Open a file or paste the content, then confirm the header and delimiter settings.
- Pick the JSON shape or the CSV delimiter you want out.
- Press Convert, then copy the result or download it.
Common Pitfalls
- Header treated as data: if the first row looks like a value, set the header toggle to match the file.
- Wrong delimiter: a semicolon or tab export parsed as comma will collapse into one column. Set the delimiter or leave it on auto.
- Deeply nested JSON: without flattening, nested objects stay whole and do not map cleanly to columns. Turn flattening on for tabular output.
- Leading zeros: quoted values keep their intended form, so check a sample before importing if IDs must stay as text.
When to Convert
- Building a JSON test payload from a spreadsheet export.
- Loading tabular data into a document store that expects JSON records.
- Handing a developer a JSON file when your source is a CSV report.
- Turning an API response into a CSV a colleague can open in a spreadsheet.
- Producing newline-delimited JSON for a bulk import or log pipeline.
Beyond One File
The converter handles one file at a time. When you need to clean, match or reconcile many files, the Flookup Data Wrangler add-on brings fuzzy matching and deduplication into Google Sheets. The free CSV Editor covers the inspection and cleaning step before you convert.
Converting Between Formats Should Take Seconds
Moving between CSV and JSON is one of the most common data tasks there is and it should not need a script or an upload. The converter gives you both directions, three JSON shapes and control over delimiters, with a copy and a download at the end.
Because everything runs locally, you can convert sensitive exports without a second thought.
For repeatable conversion next to your spreadsheet data, Flookup Data Wrangler brings matching and cleaning templates into Google Sheets.