CSV to JSON converter
Convert CSV tables into JSON records while preserving identifiers such as 0012 and long numbers as text. Check headers and records before exporting the complete result.
Converters
CSV to JSON converter
Convert CSV tables into JSON records while preserving identifiers such as 0012 and long numbers as text. Check headers and records before exporting the complete result.
Strings are preserved by default. Optional inference converts safe numbers and booleans, not dates or unsafe integers. Review identifiers before enabling it.
Maximum 2 MiB UTF-8 and 10000 records.
02Preview
.json≡ → [ ]
Add an input and run the conversion to see your result.
First 100 records and 50 columns only. Copy and download include the complete result.
02 / How to use it
About this tool
How to use this tool
Input
Paste a table with a header or import a .csv, .tsv or .txt file. Quote cells that contain delimiters or line breaks.
Options
Select the actual file delimiter. Leave inference off if every value must remain text.
Result
Select Convert. Fix any indicated record, review the table and copy or download the complete JSON.
Worked example
Worked example · CSV to JSON converter
With inference off, 0012 stays a string. The CSV header becomes a property name on every object.
Input
id,name 0012,Ana 0013,João
Result
[
{ "id": "0012", "name": "Ana" },
{ "id": "0013", "name": "João" }
]Formats and limits
- Limits
- Maximum 2 MiB UTF-8 and 10000 records.
- Options
- Yes. By default every value is a string, so 0012 stays "0012". Do not enable inference for identifiers whose formatting matters.
- Result
- Only when you enable the option. Safe numbers and booleans are converted; dates and integers outside the safe range remain text.
Common issues
What happens to duplicate headers?
They are rejected to prevent overwritten values. Each column needs a non-empty, unique header. Errors identify the affected logical record.
How are quotes and line breaks handled?
A quoted cell can contain delimiters and line breaks. Escape a quote inside it by doubling it. Every record must have as many cells as the header.
Review the result before using it
With inference off, 0012 stays a string. The CSV header becomes a property name on every object.
Formats and limits
Maximum 2 MiB UTF-8 and 10,000 records. Processed in this browser. No data is uploaded or saved.
Frequently Asked Questions
Are leading zeros preserved?
Yes. By default every value is a string, so 0012 stays "0012". Do not enable inference for identifiers whose formatting matters.
When are types inferred?
Only when you enable the option. Safe numbers and booleans are converted; dates and integers outside the safe range remain text.
What happens to duplicate headers?
They are rejected to prevent overwritten values. Each column needs a non-empty, unique header. Errors identify the affected logical record.
How are quotes and line breaks handled?
A quoted cell can contain delimiters and line breaks. Escape a quote inside it by doubling it. Every record must have as many cells as the header.
Are all rows exported?
Yes. The preview is limited to 100 records and 50 columns; copy and download include the complete result within the input limits.