Convert CSV to JSON online

Convert CSV to JSON in three steps

This converter turns a CSV file or pasted CSV text into JSON, right in your browser. 1. Paste your CSV into the input box or choose a file of up to 5 MB. The tool detects whether your file uses a comma, semicolon, tab or pipe as its delimiter. If the detection is wrong, choose the delimiter yourself. The result appears immediately: the number of rows and columns, a preview table with the first five rows, and the JSON itself.

2. Choose the output shape. An array of objects uses the first row as column names, so every row becomes an object like {"customer": "Jansen BV", "amount": "12.50"}. This is the shape most APIs and import functions expect. An array of arrays keeps the rows as lists, which is handy if your CSV has no column names or you process the data further in code.

3. Copy puts the JSON on your clipboard and Download saves it as a .json file. Your file is read with your browser's FileReader and never leaves your computer, so you can safely convert exports containing customer or order data.

Numbers, yes/no values and decimal commas

In a CSV, everything is text. By default it stays that way in the JSON too, so nothing is lost. If you turn on Convert numbers, "42" becomes the number 42 and "0.5" the number 0.5. Values with a leading zero, such as postcodes, phone numbers and product codes, deliberately stay text: as a number, 0612345678 would lose its first zero.

Excel exports from many European countries, including the Netherlands, Germany, France and Spain, usually use a semicolon as the delimiter and a comma as the decimal separator, so 12,50 instead of 12.50. In that case, also turn on Decimal comma. Then 12,50 becomes the number 12.5 and 1.249,50 the number 1249.5. With that option off, 12,50 stays text, so a wrong amount never slips into your JSON unnoticed.

The yes/no option converts words such as true, false, yes and no into real booleans. Empty fields can be included as null, so a receiving system can tell the difference between an empty string and a missing value. Which choice is right depends on what the system you load the JSON into expects.

How a CSV file is structured

CSV stands for comma-separated values: each line is a row, and a delimiter splits the row into fields. If a field itself contains the delimiter or a line break, it is wrapped in double quotes, like "De Vries; Zonen". A quote inside such a field is doubled: "Delivery ""round the back""" means Delivery "round the back". This tool follows those rules from the CSV standard RFC 4180, including Windows line endings and the invisible BOM character Excel puts at the start of a file.

The most common problem is a row with more or fewer fields than the header row. That is usually caused by a missing quote around text containing a comma, or by the wrong delimiter being chosen. The tool still converts the data, fills in missing fields and reports which lines differ, so you can check the source in a targeted way.

If you see odd characters such as é instead of é, the file was saved in a different character set. When reading a file, the tool tries to detect this itself and, if needed, reads it again with the Windows character set that older Excel versions use.

When to automate the conversion

Converting a CSV export to JSON is fine for loading data into a system once or testing an integration. If you do it every week with an export from your webshop, point of sale system or accounting software, it is manual work that invites mistakes: a wrongly selected column, last week's file, or an amount that arrives as text.

An automated import reads the source at a fixed time, checks every row against fixed rules and reports anomalies before they reach your records. Often the CSV step can even be dropped altogether, because both systems have an API that can talk to each other directly.