Excel Dataset to Parquet for Machine Learning

Many datasets start life in Excel. Training code loads Parquet faster, and it keeps column types.

Open the Excel to Parquet converter, drop the workbook and turn on type detection. Only the first sheet of an .xlsx file is read, and old .xls files must be saved as .xlsx first. Download the Parquet file.

Check the types, because they decide how your model sees the data. Numeric features should be numbers, dates should be dates, and ids and category labels should be text. A column with a few stray words in it will stay text, so look for them with the Data Profiler and fix them in Data Transformation first.

Look for blanks and duplicates before training, and keep the original workbook so you can trace any change. Then load the Parquet in pandas or Polars and compare the shape with the sheet.

Everything runs in your browser and nothing is uploaded.

Open the Excel to Parquet converter

Related tool pages

JSON, CSV, Parquet and Excel Converter: Convert between JSON, CSV, Parquet and Excel online for free, one file or a whole folder. It runs in your browser, so nothing is uploaded.
JSON to CSV Converter: Convert JSON to CSV in seconds. Drop a file or paste data and download the result. Private: it runs in your browser and nothing is uploaded. Large files too.
CSV to JSON Converter: Convert CSV to JSON in seconds. Drop a file or paste data and download the result. Private: it runs in your browser and nothing is uploaded. Large files too.
CSV to Parquet Converter: Convert CSV to Parquet in seconds. Drop a file or paste data and download the result. Private: it runs in your browser and nothing is uploaded. Large files too.
JSON to Parquet Converter: Convert JSON to Parquet in seconds. Drop a file or paste data and download the result. Private: it runs in your browser and nothing is uploaded.
Parquet to CSV Converter: Convert Parquet to CSV in seconds. Drop a file or paste data and download the result. Private: it runs in your browser and nothing is uploaded. Large files too.

How to use the Excel to Parquet converter: step by step

Open the Excel to Parquet converter and drop the workbook.
Turn on type detection.
Profile the data for stray values and blanks.
Download Parquet and compare the shape in your notebook.

When to use the Excel to Parquet converter

Prepare a spreadsheet for model training
Speed up loading of a dataset
Keep column types in a shared file
Archive a dataset in a smaller file

Example

Input: report.xlsx

Output: report.parquet

Frequently asked questions

Why convert Excel to Parquet?

Parquet is smaller and faster to load in tools like pandas, Spark, DuckDB and BigQuery.

Are numbers and dates kept as types?

Yes. Turn on type detection and numbers, dates and booleans are written as real column types.

How big can a file be?

It depends on your device. A few hundred MB usually works.

Which conversions does the Format Converter support?

Any direction between JSON, CSV, Parquet and Excel (.xlsx), for one file or a whole folder. Nested JSON is flattened into columns such as address.city. For Excel, the first sheet is read; old .xls files are not supported.

Tip: A column with a few stray words stays text. Find them with the Data Profiler before you train.