How to use CSV Cleaner
- Open a CSV and select its delimiter.
- Choose trim, blank-row removal and deduplication. Optionally list exact headers to keep, separated by commas.
- Clean CSV and review the row count and table preview before downloading.
Clean a four-record contact export
4 data rows become 2 after trimming, blank-row removal and exact deduplication.
Load this exact example ↗What changes—and what stays
Cleaning runs in this order: trim cells, remove blank rows, select columns, then remove exact duplicates. Selecting fewer columns can make previously different rows identical. Spreadsheet protection changes formula-like strings deliberately.
Practical limits
Up to 1 MiB per input, 80 nested levels and 50,000 structured values. CSV supports 10,000 data rows and 200 columns. JSON comparison returns at most 5,000 differences. UTF-8 files only; large jobs stop after six seconds.
Common questions
Are duplicate rows case-sensitive?
Yes. Alex and ALEX remain different. Only selected transformations change the comparison.
Does trimming rename my headers?
No. Trimming applies to data cells. The column selector requires exact header names. Headers containing commas cannot be named in that simple selector; leave it blank to keep all fields.