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CSV to JSON Converter

CSV to JSON Converter is part of Toolspire and is ready as soon as this page loads. Paste CSV — or copy cells straight from Excel or Google Sheets — and get clean JSON as you type: an array of objects, arrays, an object keyed by ID, or JSON Lines.

Runs in this tabFreeNo account

Optionsfirst row is the header, numbers converted, a.b → nested

First row is the headerOff: keys are column1, column2…Convert numbers & booleans“42” → 42, “true” → true, empty → null. Leading zeros and long IDs stay text.Nest dotted columns“address.city” becomes {“address”: {“city”: …}}.

Output

Indentation

CSV

JSON

The JSON appears here as you type. Try the Sample to see how nested objects and lists are converted.

On this page

What you can do here

Straight from Excel

Select cells in Excel or Google Sheets, copy, and paste here — tab-separated data is recognised automatically.

Proper JSON types

Numbers become numbers and true/false become booleans — without breaking IDs like 007 or 16-digit card numbers.

Nested objects

user.name and user.email columns become {"user": {"name": …, "email": …}}.

The shape you need

Objects for APIs, arrays for charts, keyed objects for lookups, or JSON Lines for big-data tools.

Handles messy files

Missing header names, duplicate columns and rows with extra or missing fields are handled and reported.

Private

Customer lists and exports stay on your device — nothing is uploaded.

The sequence

How to convert CSV to JSON

1
Add your CSV
Paste CSV, paste cells copied from Excel or Google Sheets, or click Open file to load a .csv file.
2
Check the options
Open Options to choose the output shape, indentation, and whether to convert numbers and nest dotted columns.
3
Review the JSON
The JSON appears as you type, with a count of rows and columns and notes about any irregular rows.
4
Copy or download
Click Copy, or Download a .json (or .jsonl) file.

Worth knowing

CSV to JSON Converter on Toolspire: turns each CSV row into a JSON object, using the first row as keys (or column1, column2… when there’s no header).
Detects the delimiter automatically — comma, semicolon, tab or pipe — so cells copied from Excel or Google Sheets can be pasted directly.
Converts numbers, true/false and empty cells into proper JSON values, while phone numbers, PIN codes with leading zeros and long IDs stay text.
Columns named like address.city become nested objects.
Four output shapes: array of objects, array of arrays, an object keyed by the first column, or JSON Lines — with 2 or 4 spaces, tabs or minified.
Follows RFC 4180: quoted fields, commas and line breaks inside quotes, and doubled quotes all work. Runs in this tab; data is not sent to us.

Output shapes

Shape	Looks like	Good for
Objects	[{"id": 1, "name": "Asha"}, …]	APIs, JavaScript, most uses
Arrays	[["id", "name"], [1, "Asha"], …]	Charts, compact data, keeping column order
Keyed	{"1": {"id": 1, "name": "Asha"}, …}	Looking rows up by ID
JSON Lines	{"id": 1, …} on each line	Streaming, logs, BigQuery and data pipelines

How values are converted

With Convert numbers & booleans on, 42 and 3.14 become numbers, true and false become booleans, and empty cells become null. Values that only look like numbers stay text: anything with a leading zero (phone numbers, PIN codes like 012345, employee IDs like 007) and anything longer than 15 digits (card and account numbers), because JSON numbers would lose those digits.

Switch the option off to keep every value as text exactly as it appears in the CSV.

FAQ

Questions about CSV to JSON Converter

Where does CSV to JSON Converter run?

CSV to JSON Converter runs in this tab on Toolspire. What you type or drop in is not sent to us and is not stored on a server.

Can I convert an Excel file to JSON?

Yes. Open the sheet, select the cells (including the header row), copy, and paste them here. To use a file instead, save it from Excel as CSV UTF-8 and open that.

Why are some numbers kept as text?

Numbers with leading zeros or more than 15 digits would change if stored as JSON numbers, so they stay text. Turn off “Convert numbers & booleans” to keep everything as text.

What if my CSV uses semicolons?

The delimiter is detected automatically — commas, semicolons (common in Europe), tabs and pipes all work. You can also pick one yourself.

Is my data uploaded?

No. The conversion runs entirely in this tab; your file never leaves your device.

How do I get nested JSON?

Name the columns with dots, like address.city and address.pin, and keep “Nest dotted columns” on. They become {"address": {"city": …, "pin": …}}.

Can I convert JSON back to CSV?

Yes — switch to JSON → CSV, or use the JSON to CSV Converter, which also shows the result as a table.

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Last updated 30 September 2026Report a problem or suggest a feature