Transform, clean and convert CSV and JSON online

Explore, refine, filter and map CSV and JSON without uploading data to a server.

Bring in your data

Paste CSV or JSON, or drop a file. We detect CSV delimiters automatically and show a preview before you change anything.

Local processing: the file stays on your device

Paste data

Data Transformer is a free tool for preparing CSV and JSON files without writing code. Remove empty rows and duplicates, trim values, rename columns, filter records, replace text and normalize dates. Everything runs in your browser and the result can be exported as CSV or JSON.

How to use this tool

Choose CSV or JSON and paste your data, or open a file from your device. Start the import to inspect its columns and rows.
Trim surrounding whitespace, remove empty rows, then remove duplicates. You can also filter records, replace values and normalize dates.
Select, rename and reorder the columns to export. Review the result and download it as CSV or JSON.

Example input and result

A list contains extra whitespace, a repeated record and an empty row. Apply trimming, empty-row removal and deduplication in that order.

Input

name,email
 Alice Test ,alice@example.com
Alice Test,alice@example.com
Bob Test,bob@example.com
,

Result

name,email
Alice Test,alice@example.com
Bob Test,bob@example.com

Supported formats

Accepts CSV with headers and automatically detected comma, semicolon or tab delimiters. Quoted fields, doubled quotes and line breaks inside cells are supported.

For JSON, use an object or an array of objects. Values become text cells; nested objects and arrays remain JSON text inside a cell. CSV exports use commas, while JSON exports contain an array of objects with string values.

Limits and useful checks

Files opened from your device are limited to 10 MiB. Performance depends on available memory and row count: try a sample first on mobile devices.
Deduplication compares the entire row. It does not automatically merge similar records; check the source date format before normalizing dates.

Frequently asked questions

Do I need an account to transform data?

No. Manual import, transformations and export work without an account. Sign in to save and reuse transformations.

Does searching the table change the exported file?

No. Preview search and sorting help you explore the data. Apply a filter transformation to change the rows included in the export.

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