CSV to JSON converter
Turn a CSV spreadsheet into an array of JSON objects.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.csv up to 25 MB. You can also drag a file here.
No file selected.
About this tool
Spreadsheets export CSV, but most APIs, configuration files, and scripts want JSON. This tool reads a CSV file and writes an array of JSON objects, using the header row for the property names.
Parsing is streamed in chunks rather than loaded all at once, so a large export stays responsive instead of freezing the page while it reads.
Supported formats and limits
- Input
- .csv
- Output
- .json (application/json)
- Output name
- The original name with the new extension, for example data.csv becomes data.json.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
How to use it
- Choose a .csv file, or switch to Paste text and paste the rows directly.
- Confirm whether the first row holds column names.
- Choose whether to indent the JSON.
- Select Convert, then download the .json file.
Limitations
- Every value becomes a string. Numbers, booleans, and dates are not guessed at, because guessing silently corrupts things like postcodes, phone numbers, and version strings that only look numeric.
- Without a header row, columns are named column1, column2, and so on.
- Duplicate column names collapse: the last column with a given name wins.
- A row with fewer fields than the header gets empty strings for the missing ones. A row with extra fields loses them.
- The file is read as UTF-8. A file saved in a legacy encoding may show damaged characters.
Frequently asked questions
- Is my file uploaded?
- No. The conversion runs entirely in your browser. The file never leaves your device and no request carrying its contents is made.
- Why are my numbers quoted in the output?
- CSV carries no type information, so every field is kept as text. Converting "007" to the number 7 or a long account number to scientific notation loses data that cannot be recovered, so values are left exactly as written.
- Does it handle quoted fields and embedded commas?
- Yes. Quoted fields, escaped quotes, and line breaks inside a quoted value are all parsed correctly.
- What about semicolon-separated files?
- This tool expects commas. A semicolon-separated export from a European spreadsheet will come out as a single column, so re-export it with commas first.
- How large a file can it handle?
- The limit is 25 MB. Files over a few megabytes are still parsed in chunks so the page keeps responding, but conversion takes longer and needs more memory on phones.