Add Conditional Column to Parquet Files Online
Add a new column to Parquet files based on an if/else condition directly in your browser. Set a value for rows that match and a different value for rows that don't — no upload required.
About this tool
Add a new column to a Parquet file whose value is determined by conditions you define — like an Excel IF statement or SQL CASE WHEN. Set as many rules as you need, choose a value for each matching condition and a fallback for everything else, then download the updated file. All processing runs locally in your browser.
Frequently Asked Questions
What is a conditional column in a Parquet file?
A conditional column adds a new column whose value is determined by rules you define — equivalent to SQL CASE WHEN. For example: if score > 90 then "A", if score > 80 then "B", else "C". Each row gets the label from the first condition it satisfies.
Can I add multiple conditions when creating a conditional column in a Parquet file?
Yes. Add as many WHEN conditions as you need. Conditions are evaluated top to bottom and the first match wins. The final ELSE clause sets the value for any row that matches none of the conditions.
What data types can I use in conditional column expressions for Parquet files?
Text, numeric, and date comparisons are all supported. Operators include equals, not equals, greater than, less than, contains, starts with, ends with, is null, and is not null.
Is my data private?
Yes — completely. Your file is never uploaded to any server. Everything runs locally in your browser using WebAssembly — processing happens entirely inside your tab. Once you close the tab, nothing is retained.
What is the maximum file size?
The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines handle 500 MB to 1 GB comfortably.
Related Tools
Add Moving Average to Parquet Files Online
Add a moving average, rolling sum, rolling min, or rolling max column to Parquet files directly in your browser. Choose window size, order-by column, and optional partitioning — no upload required.
Search Text in Parquet Files Online
Search for text across all string columns in Parquet files directly in your browser. Filter rows to only those containing your search term and download the results — no upload required.
Get Top N Rows from Parquet Files Online
Extract the top N rows per group from Parquet files directly in your browser. Get the top 5 products per category, highest scores per team, or any ranked subset — no upload required.
Add Percent of Total to Parquet Files Online
Add a percentage-of-total column to Parquet files directly in your browser. Show each row's share of the grand total, or the share within each group — no upload required.
Parse URL Column in Parquet Files Online
Parse URL columns in Parquet files and extract host, path, query string, and fragment into separate columns — directly in your browser, no upload required.