How to Convert CSV to JSON Online for Free
CSV (Comma-Separated Values) is great for spreadsheets, but modern web applications and APIs typically use JSON (JavaScript Object Notation). Converting CSV to JSON lets you use tabular data in web apps, APIs, and databases that expect JSON format. This guide shows you how to convert CSV to JSON using fixie.tools — completely free, no signup required, with instant browser-based conversion.
Step 1: Open the CSV to JSON Converter
Navigate to fixie.tools/csv-json in your web browser. The tool works entirely in your browser, so your data never leaves your device. No account creation or file uploads to servers required.
Step 2: Input Your CSV Data
Either paste CSV data directly into the text area or upload a CSV file from your computer. The tool supports standard CSV format with comma delimiters, though you can also handle TSV (tab-separated) or other delimiters. The first row is automatically treated as column headers, which become the JSON object keys.
Step 3: Choose JSON Output Format
Select your preferred JSON structure from the available options. Array of Objects is the most common format where each CSV row becomes a JSON object with column headers as keys. Array of Arrays converts rows to nested arrays (useful for compactness). Keyed JSON uses the first column as object keys. Column Arrays groups data by column instead of by row. Choose based on how your application expects to consume the data.
Step 4: Configure Conversion Options
Adjust settings for your specific needs. Enable type detection to automatically convert numbers and booleans instead of treating everything as strings. Configure how empty cells are handled (null, empty string, or omitted). Set custom delimiter if your CSV uses semicolons or tabs instead of commas. Enable pretty-printing for human-readable JSON with indentation, or disable it for compact output.
Step 5: Copy or Download JSON
Once converted, you'll see the JSON output instantly. Click the Copy button to copy the JSON to your clipboard for pasting into code or tools. Or download as a .json file if you need to save it or import into another application. The conversion happens instantly in your browser with no server upload or processing delays.