Keep identifiers intact
Customer codes, telephone numbers and postcodes can contain leading zeros. CSV to JSON keeps values as strings rather than guessing a numeric type.
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A practical example
Keep leading zeros when converting customer data
For CSV columns name and postcode with a row Alex,00123, the resulting JSON keeps postcode as the string “00123”. Identifiers should not silently become numbers.
- Paste or import the CSV and choose comma, semicolon or tab as its separator.
- Use the first row as headers, preview the objects and download JSON.
Check header names and quoted values. Conversion changes structure; it does not validate the business meaning of each field.
Back to the toolAbout the csv to json: instructions and questions
Convert CSV rows into JSON objects with header names.
How to use the csv to json
- Paste data or choose a file. Use a local text file up to 2 MB, or paste its contents into the input.
- Check the options. Choose the CSV separator. CSV to JSON uses the first row as headers; JSON to CSV expects an array of record objects.
- Review and download. Check the preview, then save the converted file. The tool runs entirely in this browser tab.
Make the next step easier
Move business data into a useful format.
Convert a small export for a spreadsheet, a developer handover or another business tool. Check the source data and keep a copy before importing the result elsewhere.
Check before importing
The converter changes structure, not business meaning. It does not validate addresses, calculate totals or clean inaccurate records. Review headers, delimiters and sample rows in the result.
CSV to JSON questions
Is this free without an account?
Yes. There is no signup, payment gate or added watermark. The stated limits keep the work manageable on your device. Your result is a normal downloadable file.
Are my files uploaded?
No. These tools read and process files in your browser tab. File contents are not sent to a conversion server or a paid API. Download the result before closing the tab. Normal website hosting and page analytics still apply.
Which CSV separators can I use?
Choose comma, semicolon or tab. Quoted values can contain the separator, doubled quotes and line breaks. The converter checks rows for consistent column counts.
How are values converted?
CSV to JSON keeps cell values as strings so leading zeros and identifiers are not silently changed. JSON to CSV serialises nested objects and arrays as JSON inside a cell, and leaves missing or null values empty.
What are the limits?
Use up to 2 MB of text, 10,000 rows and 200,000 cells. Duplicate or empty CSV headers and invalid JSON are reported. JSON to CSV requires an array of objects, not a single object.
Can I open the CSV in a spreadsheet?
Yes. Choose the separator your spreadsheet expects. Formula protection is enabled by default for JSON to CSV and prefixes formula-like strings with an apostrophe. You can turn it off when you need unchanged trusted values.
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