Count, sum, or average CSV rows grouped by any column
Aggregate CSV rows by one or more group-by columns with count, sum, mean, min, or max.
🛡️ Your rows never leave your browser.
Why Onfyt: Supports multi-column group keys and per-column aggregation functions in a single operation—no need to run multiple passes.
Interactive Sample Data
| region | product | amount |
|---|---|---|
| Nairobi | Solar | 4500 |
| Mombasa | Inverter | 3200 |
| Nairobi | Inverter | 2800 |
How this tool works
Group-by aggregation is the most common summary operation in data analysis—equivalent to SQL's GROUP BY clause or Excel's SUMIF/COUNTIF functions. It collapses thousands of individual records into a compact summary table: total sales by region, order counts by product category, or average response time by server region.
DataFix supports grouping by multiple columns simultaneously and applying independent aggregations to different value columns in the same pass.
Group-by and count summarizes large tabular datasets by grouping records matching identical keys and computing total occurrences. This operation is indispensable for customer segmentation, inventory reconciliation, error log analysis, and survey tallying. DataFix aggregates rows against single or composite grouping keys, computing frequencies and percentages with high performance in Web Workers, producing a clean, exportable summary table ready for immediate presentation or reporting.
Frequency aggregation identifies key cohorts, recurring categories, and operational volumes across large datasets. Computing group totals and distinct frequencies directly in your browser provides rapid summary analytics without database overhead.
Aggregating categorical records into frequency tables reveals high-volume customer segments, top product categories, and recurring system log errors. Computing these distinct counts in-memory provides rapid analytical insights without spinning up external database infrastructure.
Things that usually go wrong
- Trailing spaces in values create separate groups (e.g. 'Nairobi' and 'Nairobi '). Use Trim Whitespace first.
- Case differences also split groups: 'Solar' and 'solar' become two groups. Normalize case first.
Edge cases we tested
🧪 Group-by column with trailing whitespace in values
Trimmed before grouping so ' Nairobi' and 'Nairobi' are treated as the same group.
🧪 Sum on a column with mixed numeric and 'N/A' strings
Non-numeric values excluded from sum; count of excluded rows reported.
🧪 Group on two columns simultaneously
Composite key (region + product) used; all unique combinations produced.
Frequently Asked Questions
Can I group by multiple columns?
Yes — select multiple columns as group keys. Each unique combination produces one output row.
What aggregations are supported?
Count, sum, average, min, and max.
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