CSV to JSON Converter

How the CSV to JSON conversion works

CSV (comma-separated values) is the universal export format of spreadsheets, CRMs, shops and databases. JSON is what web APIs, JavaScript apps and NoSQL databases expect. This CSV to JSON converter bridges the two while following RFC 4180, the CSV standard, so quoted fields that contain commas, quotes or line breaks are read correctly.

Given this CSV:

name,email,plan,active
Ana,ana@example.com,pro,true
"Lee, Sam",sam@example.com,free,false

the default output is an array of objects, one per row, with the header row as keys:

[
  {"name": "Ana", "email": "ana@example.com", "plan": "pro", "active": true},
  {"name": "Lee, Sam", "email": "sam@example.com", "plan": "free", "active": false}
]

Delimiter and type detection

The delimiter is detected from the first line: comma, semicolon (common in European Excel exports), tab (TSV) or pipe. With Detect numbers, booleans and null on, 30 becomes a number and true a boolean. Long numeric IDs, phone numbers and values with leading zeros like 00123 stay as strings so nothing is lost or rounded.

Choose the right JSON structure

Tick Nest dot headers to turn columns like user.name and user.email into a nested "user": {"name": ..., "email": ...} object. Other clean-up options trim spaces, skip empty rows and turn empty cells into null.

Convert JSON to CSV for Excel and Sheets

The JSON to CSV tab does the reverse. Paste an array of objects, an API response that wraps the array (like {"data": [...]}), or NDJSON with one object per line. Nested objects are flattened into dot-notation columns, and the header is the union of every key found, so rows with missing fields still line up.

Choose semicolon as the CSV delimiter if Excel in your region puts everything in one column, or tab for a TSV that pastes cleanly into any spreadsheet. If your JSON is invalid, run it through the JSON formatter first to see the exact line and column of the error. The JSON formatter also has its own JSON to CSV and YAML export.

Tips for clean CSV to JSON exports

• Excel exports: save as "CSV UTF-8" so accented characters survive. A UTF-8 byte order mark is removed automatically.
• Duplicate or blank headers are renamed (email_2, column_3) so no data is overwritten.
• Ragged rows with too few or too many fields are reported, and missing cells are filled with empty values.
• Large files: up to 3 MB or 50,000 rows per conversion. Split bigger files and convert them in parts.
• Cleaning a list before converting? Remove repeated rows with Remove Duplicate Lines.

A complete CSV to JSON example

Here is a small CSV with a nested header, a number, a boolean and an empty cell:

id,user.name,user.city,score,active,notes
101,Ana,Galle,92.5,true,
102,Ravi,Kandy,88,false,needs review

With Nest dot headers, type detection and Empty cells as null turned on, the output is:

[
  {"id": 101, "user": {"name": "Ana", "city": "Galle"}, "score": 92.5, "active": true, "notes": null},
  {"id": 102, "user": {"name": "Ravi", "city": "Kandy"}, "score": 88, "active": false, "notes": "needs review"}
]

Switch the shape to Object keyed by a column with id as the key and you get {"101": {...}, "102": {...}}, which is ideal for quick lookups in JavaScript. Choose NDJSON and each object is written on its own line, ready for bq load or an Elasticsearch bulk import.

CSV to JSON Converter: frequently asked questions