Free CSV to JSON Converter Online

FJ Techtools provides a free CSV to JSON converter that works entirely in your browser. Paste your CSV data directly into the editor or upload a file, and the tool converts it to JSON instantly — no server upload, no signup, and no waiting. The result can be copied to clipboard or downloaded as a .json file.

This tool is useful for developers working with APIs, data analysts preparing datasets for web applications, and anyone who needs to move tabular data from spreadsheets or exports into a JSON-compatible format.

How to convert CSV to JSON online

Paste your CSV data into the input editor or click "Upload CSV file" to load a file from your device. The tool automatically detects the delimiter and converts the data to JSON in real time — you'll see the output update as you type. Once satisfied, click Download to save the .json file, or Copy to grab it to your clipboard.

Conversion options explained

This converter includes several options that give you control over the output format:

Separator — auto-detects comma, semicolon, or tab-delimited files, or you can set it manually if auto-detection picks the wrong one.
Minify — removes whitespace and line breaks from the JSON output, producing a compact single-line string suitable for embedding in code.
Parse Numbers — converts numeric strings like "42" to actual JSON numbers 42 instead of keeping them as strings.
Parse JSON — if any CSV cell contains a JSON string, this option parses it into a nested object rather than leaving it as a plain string.
Hash — outputs the JSON as a key-value object using the first column as the key, instead of an array of objects.
Transpose — swaps rows and columns before converting, useful when your CSV data is oriented horizontally rather than vertically.

When would you convert CSV to JSON?

CSV is the standard export format for spreadsheet applications like Excel and Google Sheets. JSON is the standard data format for web APIs, JavaScript applications, and NoSQL databases like MongoDB. Common conversion scenarios include loading spreadsheet data into a REST API, seeding a database with exported records, transforming analytics exports for use in a front-end chart library, and preparing configuration data for a web application.

For the reverse operation, use the JSON to CSV converter. To format or inspect your JSON output, use the JSON Beautifier.

Frequently Asked Questions About CSV to JSON Converter

How do I convert a CSV file to JSON?

Paste your CSV data into the input editor or click Upload CSV file to load a file from your device. The tool converts it to JSON automatically in real time. Click Download to save the result as a .json file or Copy to grab it to your clipboard.

Does this tool support semicolon and tab-delimited CSV files?

Yes. The separator dropdown includes auto-detect, comma, semicolon, and tab options. Auto-detect works for most files, but you can override it manually if needed.

What does the Parse Numbers option do?

When enabled, numeric strings like "42" are converted to actual JSON numbers (42) instead of remaining as strings. This is useful when the JSON output will be consumed by an application that expects numeric types.

Can I convert a CSV file with headers to a JSON array of objects?

Yes. When your CSV has a header row, the tool uses those headers as keys and produces a JSON array of objects — one object per row. This is the standard output format compatible with most APIs and databases.

Is there a file size limit for CSV uploads?

This tool is browser-based with no server upload, so there is no strict file size limit. Very large files may slow down the conversion depending on your device's processing speed.

How do I convert JSON back to CSV?

Use the JSON to CSV Converter for the reverse operation.

Free CSV to JSON converter online — paste or upload CSV and download JSON instantly

CSV to JSON Converter Online