Common CSV workflows
CSV has no native number or NULL type, so a converter has to infer them. TSV avoids most quoting, but values that contain tabs or line breaks still need it. Excel stores at most 15 significant digits and turns long IDs into rounded numbers. Each converter documents its mapping; check the result against the source before importing it elsewhere.
Turn a spreadsheet into JSON
Select a worksheet from an XLSX file, inspect the rows, then convert to JSON with typed or string values. Long numeric IDs should stay strings.
- Excel to JSON / CSV — Convert Excel worksheets to JSON / CSV and back.
- CSV Viewer — Open CSV files as a sortable, searchable table.
- CSV to JSON — Convert CSV to JSON objects, arrays or JSON Lines.
Inspect a large export
Page through NDJSON, Parquet or Avro files in a worker without loading everything into memory, then export the rows you need as JSON or CSV.
- Data File Lab — Page through NDJSON, Parquet, Avro, Protobuf and hex.
- CSV Viewer — Open CSV files as a sortable, searchable table.
- JSON to CSV — Convert JSON arrays to CSV, flattening nested objects.
Prepare data for a spreadsheet
Flatten JSON records into columns, or convert TSV copied from a database client. Enable formula protection when the file will be opened in Excel or Google Sheets.
- JSON to CSV — Convert JSON arrays to CSV, flattening nested objects.
- TSV Converter — Convert tab-separated data, CSV and JSON.
- Excel to JSON / CSV — Convert Excel worksheets to JSON / CSV and back.
Conversions can change types
Excel supports only 15 significant numeric digits, and CSV cannot distinguish an empty string from NULL by itself. Read the tool’s precision notes and keep the original file.
Protect files that will open in a spreadsheet
A cell that starts with =, +, - or @ can run as a formula when the file is opened. JSON to CSV, the TSV converter and SQL to CSV can prefix such cells so they open as text.
Frequently asked questions
Does conversion always preserve every value?
No. Formats have different type systems and numeric limits. For example, CSV cannot distinguish an empty string from NULL by itself. Each converter documents its mapping and unsupported cases.
How large a file can I open?
The CSV viewer parses files of several megabytes in a fraction of a second, and Data File Lab indexes larger files in a worker and reads them in bounded pages. The limit is your device’s memory, not an upload size.
Tools process your input on this device. Read the privacy policy, or save the tool library for offline use.