CSV to JSON converter
Convert a CSV or Excel file to JSON in your browser. Use the header row as field names, keep numbers and booleans as real values, and nest columns like score.math. Free, nothing is uploaded.
When to use it
Web apps, APIs and many databases want JSON, but data often starts life as a spreadsheet or a CSV export. This tool turns each row into a JSON object, using the header row as the field names.
You can keep numbers and true/false as real values, turn column names like score.math into nested objects, and choose a readable array, a compact array or JSON Lines. Copy the result or download it as a file.
How it works
- Drop in a CSV or Excel file, or press the example button.
- Choose whether the first row is a header, and how to treat numbers, empty cells and nested names.
- Copy the JSON or download it as a .json or .jsonl file.
Questions
What does the JSON look like?
An array with one object per row. The header row gives the field names, so a row like Ayesha,Paris becomes {"name":"Ayesha","city":"Paris"}.
Will numbers stay as numbers?
Yes, if you leave the types option ticked. Plain numbers and true/false become real JSON values. Codes with leading zeros, such as 007, stay as text so they are not changed. Untick the option to keep every value as text.
Can I get nested JSON?
Yes. Tick the nesting option and a column named score.math is written as {"score":{"math":91}}. This is the reverse of what the JSON to CSV tool does.
What is JSON Lines?
JSON Lines (.jsonl) puts one JSON object on each line. It is handy for large files and for tools that read records one at a time.
Is my file uploaded anywhere?
No. The conversion runs in your browser tab and nothing is sent to a server.
Did this help?
Tell me what worked, what broke, or what tool you want next. I read every message.
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