How to convert CSV to Excel, and Excel to CSV or Parquet

Online converters want you to upload the file first. For a customer export or a payroll sheet that is a bad trade just to change the format. The conversion can happen on your own computer instead.

Convert in two clicks

Open NoEgress and drop a CSV, TSV, Excel, JSON or Parquet file. On the Start page, Convert and download has three buttons: CSV, Excel and Parquet. Click the one you want and the file downloads.

For an Excel workbook with several sheets, pick the sheet first; each sheet is its own table.

When Excel is not an option

An Excel sheet holds at most 1,048,576 rows. For a larger file the Excel button is disabled and CSV or Parquet is the way to go. That limit is also why large CSVs open cut off in Excel.

Why Parquet

Parquet stores data by column, compressed, with the types kept. The same table is usually much smaller than the CSV, and dates stay dates instead of becoming text. Python, R, Power BI, Spark and DuckDB all read it.

Use it when the file goes to an analyst or a data pipeline rather than a person with a spreadsheet.

Fix things on the way

Converting is a good moment to fix types, rename columns or drop the ones nobody needs. Do it in SQL, then export the result.

SELECT
  TRIM(customer_name)      AS customer,
  CAST(amount AS DOUBLE)   AS amount,
  CAST(order_date AS DATE) AS order_date
FROM orders;