CSV to JSON

This CSV to JSON converter turns spreadsheet data exported from Excel or WPS into an array of objects. The first row is used as the field names, numbers, booleans and null can be type-inferred, and the delimiter is detected automatically. Parsing runs locally in your browser, so the table data does not leave your machine — handy for bulk API test data.

Open in the workbench Runs locally · nothing is uploaded

How to use it

1
Paste your CSV
The first row must be the column names (header); each following row becomes one JSON object.
2
Choose type inference
By default 28 is inferred as a number and true as a boolean; untick the option to keep everything as strings and reconvert instantly.
3
Copy the JSON array
Choose 2 or 4 space indentation and copy the result for an API payload or mock data.
4
Verify the shape
Check that the field names and inferred types match your expectations before using the output.

Key features

Smart type inference

Numbers, true/false, null and empty cells are converted to the matching JSON types; turn it off to keep everything as strings.

Automatic delimiter detection

Comma, semicolon, tab and pipe delimiters are all detected automatically, and you can set one manually.

Full quoting support

Quoted fields containing commas, double quotes or line breaks are parsed correctly, and an unclosed quote reports its line.

Tolerant of short rows

A row with too few columns gets null for the missing fields instead of aborting the whole conversion.

Keeps spreadsheet order

The resulting array keeps the row order of the source table.

Local and private

Parsing happens in your browser and the table data is not uploaded.

Common errors & troubleshooting

! The first row must be the header; for headerless data, add a row of column names first.
! Values with leading zeros, such as employee IDs, ID numbers or 007, should have type inference turned off, otherwise they become numbers and lose the leading zero.
! An empty cell becomes null; if you need an empty string, write "" explicitly in the source table.
! Use UTF-8 encoding (Excel: Save As → CSV UTF-8) to avoid garbled non-ASCII text.

Frequently asked questions

What are the type inference rules?

Plain integers, decimals and scientific notation become numbers, true/false become booleans, null and empty cells become null, and everything else stays a string. When unsure, turn inference off to keep all values as strings.

Is there an encoding requirement for the CSV file?

UTF-8 is recommended (Excel: Save As → CSV UTF-8). Non-ASCII text in a legacy encoding may appear garbled because of how the browser reads local files, which is unrelated to the conversion logic.

What if a cell contains a comma and a line break?

In standard CSV such content is wrapped in double quotes, and the tool fully supports the quoting syntax. If you see a quote error, check that the quotes in that cell are paired.

Is my data uploaded?

No. Parsing happens locally in your browser.

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