CSV to JSON
Convert CSV data into structured JSON.
This tool runs entirely in your browser. Your data never leaves your device — nothing is uploaded to our servers.
About CSV to JSON
CSV looks simple until real data arrives. A field containing a comma must be quoted; a field containing a quote must escape it by doubling; line breaks can appear inside a quoted field, so splitting on newlines corrupts the file. This converter parses CSV properly rather than splitting on delimiters, uses the first row as object keys, and runs in your browser — which matters, because CSV exports are usually customer lists.
When to use CSV to JSON
Loading a spreadsheet export into an app
Turn an exported sheet into a JSON array you can seed a database or fixture file with.
Preparing a request body
APIs take JSON, business teams produce spreadsheets. This converts between the two without a script.
Inspecting an export safely
Customer and payroll exports contain personal data. Local conversion keeps that data off third-party servers and out of GDPR trouble.
Limitations worth knowing
- The first row must be a header. A file starting straight into data will have its first record consumed as column names.
- Every value is produced as a string. Numbers and booleans are not inferred, because guessing types silently corrupts data such as leading-zero postcodes.
- Duplicate column names collide — later columns overwrite earlier ones, since object keys must be unique.
- Very large files may exhaust browser memory; multi-hundred-megabyte exports belong in a streaming script.
How to csv to json
- 1
Paste your CSV, or load the file — the first row is treated as the header.
- 2
Check that the detected columns match what you expect.
- 3
Convert to get an array of objects, one per data row.
- 4
Copy the JSON output or download it.
Frequently asked questions
Why are my numbers strings in the output?+
Deliberately. Automatic type inference is a classic source of silent data corruption — postcodes like 01234 lose their leading zero, long IDs lose precision, and values like NaN or version numbers get mangled. Keeping everything as strings preserves your data exactly; cast the specific fields you know are numeric.
My CSV has commas inside the values. Will that break it?+
No, provided those fields are quoted, as the CSV convention requires. The parser handles quoted fields containing commas, escaped double quotes, and even line breaks inside a quoted field — cases that a naive split-on-comma approach gets wrong.
Is my data uploaded anywhere?+
No — conversion happens entirely in your browser. This is the main reason to use a client-side converter for CSV: exports are typically customer records, employee data or financial rows, and uploading those to an unknown service can itself be a reportable data-protection breach.