From a table to JSON
CSV is the most common way to get data out of Excel, Google Sheets or a database, but apps and APIs work with JSON. This tool turns each CSV row into a JSON object and uses the first row as the field names.
It detects the delimiter on its own (comma, semicolon, tab or pipe) and respects quoted fields, including ones with commas or line breaks inside. With “Detect numbers, true/false and null” on, numeric values come out as numbers; codes with leading zeros, like the ZIP code 02134, and numbers that are too long stay as strings so no digits are lost.
If your columns are named “address.city” or “address.zip”, you can turn on “a.b columns as nested objects” and get {"address": {"city": ..., "zip": ...}}.
How to convert CSV to JSON
- Paste the CSV or open a .csv or .tsv file.
- Leave the delimiter on “Detect” or pick one.
- Say whether the first row holds the column names.
- Click “Convert to JSON” and copy or download the result.
When to use it
- Loading data that someone maintains in Excel into an app.
- Building test data or fixtures from a spreadsheet.
- Sending records exported from a CRM or an online store to an API.
- Turning a translations or product table into a JSON file.
Frequently Asked Questions
Does it work with semicolon-separated CSV?
Yes. The delimiter is detected automatically from the first few lines. If detection gets it wrong, pick comma, semicolon, tab or pipe by hand.
What if a cell contains commas or line breaks?
If the cell is wrapped in double quotes, as Excel does when exporting, it's read in full even if it contains commas, line breaks or doubled quotes ("").
Why does a number come out as a string?
So no information is lost: values with leading zeros (ZIP codes, phone numbers) and integers longer than 15 digits are kept as strings. If you'd rather have everything as strings, turn off “Detect numbers”.
Is my data sent to a server?
No. Everything is processed in your browser with JavaScript. The text you paste and the files you open never leave your device, so you can safely work with internal or customer data.
Can I convert several CSV files at once?
Yes, with ToolStudio Pro: open several files and download all the JSON files together in one ZIP.
Is it free?
Yes. You can try the tool for free on one document (pasted or a single file) and change the options as often as you like; attempts that end in an error don't use up your free try. For unlimited use and processing several files at once, ToolStudio Pro costs €1.99 a month and includes every tool.
