How to Convert CSV to JSON (With Proper Numbers and Booleans)

Spreadsheets are where data lives. JSON is what code wants. Converting between them by hand, or with a quick script that then chokes on a comma inside quotes, is a classic time-sink.

What you get

With First row: Is a header (objects), this CSV:

name,city,orders,active
Ana Silva,Lisbon,12,true
Bob Lee,Leeds,3,false

becomes:

[
  { "name": "Ana Silva", "city": "Lisbon", "orders": 12, "active": true },
  { "name": "Bob Lee", "city": "Leeds", "orders": 3, "active": false }
]

Notice 12 and true aren't strings. With Is data (arrays), each row becomes ["Ana Silva", "Lisbon", 12, true] instead.

How to convert CSV to JSON with ZapMorph

1. Open the converter

Go to the CSV to JSON converter.

2. Add your CSV and choose the first-row option

Drop in .csv or .tsv files, or paste CSV text with Ctrl+V. Choose First row: header (objects) or data (arrays).

3. Convert and download

Click Convert to JSON and download.

Common gotchas

• Leading zeros: a value like 00123 (a zip code or product ID) may be read as the number 123. If that matters, adjust it in your code or quote it in the source.
• Excel exports sometimes use semicolons instead of commas in some regions. Check your file in a text editor if columns look merged.
• Empty cells become empty strings.

Other ways

• Python: pandas.read_csv("file.csv").to_json(orient="records").
• Node: libraries like papaparse or csv-parse.
• jq + Miller: mlr --icsv --ojson cat file.csv on the command line.

Related

• Going the other way? JSON to CSV.
• Need to inspect the JSON? The JSON viewer or JSON formatter.
• Need a spreadsheet instead? CSV to Excel.

Example

id,name,active
1,Ana,true

[{ "id": 1, "name": "Ana", "active": true }]

Watch out for

• IDs with leading zeros like 00123 may become numbers. If they must stay text, adjust them in your code or keep them as strings at the source.
• Empty cells come through as empty values. Decide how your app should treat them.
• Header names become keys, so keep them short and consistent (first_name, not First Name (required)).

Uses

• Seeding databases and test fixtures.
• Static websites loading data from a JSON file.
• APIs that accept JSON uploads.

Summary

The CSV to JSON converter handles quoting and typing correctly, so you get clean JSON without writing a throwaway script.