UlvixorCSV to JSON Converter
Paste your CSV and get a perfectly formatted JSON array instantly, using the first row as the field headers. Everything runs in your browser, so your data is never uploaded to a server.
How it works
- Paste or type your CSV into the input panel (or use the built-in example).
- The tool treats the first row as the header and converts each following row into a JSON object.
- The result appears as an indented JSON array, ready to use.
- If the CSV has a formatting error, a message shows exactly which row it's on.
- Copy the resulting JSON or download it as a .json file.
Use cases
- Turn an Excel or Google Sheets export into JSON for an API or script.
- Prepare mock data in JSON format from a spreadsheet.
- Migrate tabular data into a NoSQL database or a configuration file.
- Quickly inspect the contents of a CSV by viewing it as structured objects.
Use cases
- Turn an Excel or Google Sheets export into JSON for an API or script.
- Prepare mock data in JSON format from a spreadsheet.
- Migrate tabular data into a NoSQL database or a configuration file.
- Quickly inspect the contents of a CSV by viewing it as structured objects.
Common mistakes
- Expecting numeric CSV values to be automatically converted to numbers in the JSON.The tool keeps every value as text (a string), exactly as it comes in the CSV. If you need real numbers or booleans, convert them afterward in your own code.
- Pasting a CSV with no header row and expecting the columns to be detected correctly.The tool always treats the first row as the header. Add a row with column names before converting, or the first data record will be used as if it were field names.
- Leaving a field with commas unwrapped in double quotes.A field like Madrid, Spain without quotes gets interpreted as two separate columns. Wrap that value in double quotes; the parser follows the CSV standard and treats it as a single field.
Frequently asked questions
No. The CSV-to-JSON conversion happens entirely in your browser using JavaScript. Your file never leaves your device or gets uploaded anywhere.
The tool assumes the first row contains the column names. If your CSV has no header, add a first row with column names before converting.
If a field contains commas, wrap it in double quotes (for example "Madrid, Spain"). The parser follows the CSV standard and correctly handles quoted fields.
There's no fixed limit — your browser can handle files several megabytes in size without issue. For very large files, performance depends on your device's available memory.
Alternatives
In Node.js, the same library this tool uses (PapaParse) or csvtojson let you do the conversion inside a script, and in Python pandas.read_csv(...).to_json() achieves an equivalent result. This tool is handy for a one-off conversion with no dependencies to install or code to write.