About the CSV to JSON Converter
Tezmy's CSV to JSON Converter turns spreadsheet data into JSON for apps and APIs, and JSON back into CSV you can open in Excel or Google Sheets. It correctly handles quoted values, commas and line breaks inside cells, and auto-detects comma, semicolon, tab or pipe separators. Use the first row as keys, turn numbers and true/false into real JSON types, open a file directly, and download the result. Your data never leaves your browser.
Updated October 2026
How to use the CSV to JSON Converter
- 1Choose CSV → JSON or JSON → CSV.
- 2Paste your data, or open a .csv or .json file.
- 3Adjust the separator and header options if needed.
- 4Copy or download the converted data.
CSV and JSON in simple words
CSV is a simple table: each line is a row and commas separate the columns, which is what Excel and Google Sheets export. JSON is the format apps and APIs use, with named fields like {"name": "Ana", "age": 31}. Converting between them lets you move data from spreadsheets into code, and back.
Getting a clean result
- Put column names in the first row and turn on header keys, so each row becomes an object with named fields.
- Turn on number and boolean detection so 42 and true become real numbers and true/false, not text.
- If columns look merged, check the separator: many European spreadsheets use semicolons.
JSON back to CSV
Paste an array of objects to get a CSV with one column per field, ready to open in Excel or Google Sheets. Nested objects are flattened so they fit in columns. Values containing commas, quotes or line breaks are quoted correctly, so the table opens without broken rows.
Private data stays private
Spreadsheets often contain customer names, emails and prices. Here the conversion runs in your own browser and nothing is uploaded. You can open a file directly and download the result.
Convert on any device
Everything runs in your own browser, so nothing you paste is uploaded or logged. It works on phones, tablets and computers with nothing to install, and there's no sign-up. If the JSON looks messy, clean the layout with the JSON Formatter and check it with the JSON Validator. Messy lists can be cleaned with Remove Duplicate Lines before converting, and the Base64 Encoder & Decoder helps when a value arrives encoded.
Features
- CSV to JSON and JSON to CSV
- Handles quotes and commas inside values
- Auto-detects the separator
- Header row as keys
- Numbers and booleans detected
- Private: data stays in your browser
Frequently asked questions
How do I convert Excel to JSON?
In Excel or Google Sheets, save or download your sheet as CSV, then open that file here and choose CSV → JSON.
What if my values contain commas?
That's fine when those values are wrapped in double quotes, which Excel and Google Sheets do automatically. The converter reads them correctly.
Why is my CSV using semicolons?
In many European countries spreadsheets use ; because the comma is the decimal separator. Auto-detect handles this for you.
How is nested JSON converted to CSV?
Each top-level key becomes a column. Nested objects and arrays are written into their cell as JSON text so no data is lost.
Is my data uploaded?
No. Conversion happens entirely in your browser.
How do I convert a Google Sheet to JSON?
In Google Sheets, choose File, Download, Comma-separated values (.csv). Open that file here and convert it to JSON.
Is there a size limit?
No fixed limit. Files with tens of thousands of rows convert fine on most computers; very large files may be slow on older phones.
Can I format the JSON nicely?
The JSON output is indented and readable. To validate or minify it, paste it into the JSON Formatter.
Can I open an Excel .xlsx file directly?
Save it as CSV first in Excel (File, Save As, CSV) or Google Sheets, then open the CSV here.
Is it free?
Yes, free with no sign-up.