CLEAN · ENTIRELY IN YOUR BROWSER
CSV Cleaner
Clean up spreadsheet exports by trimming cell edges and removing exact duplicate rows. Change the output delimiter without breaking quoted fields.
CSV Cleaner workspace
LOCAL WORKSPACEYour converted data will appear here.
Table preview · up to 5 rows and 20 columns
A PRACTICAL EXAMPLE
See the transformation.
Input
name,city
Alex , London
Sam,Paris
Alex , London Output
name,city
Alex,London
Sam,ParisHow to use CSV Cleaner
- Paste CSV and choose its input delimiter.
- Choose trimming, duplicate removal, header preservation, and an output delimiter.
- Clean the data, compare row counts, and download cleaned.csv.
Trim cells before removing duplicate rows
When both options are enabled, trimming happens first, so rows that differ only by whitespace at cell edges can become duplicates. The first matching row is retained. This example keeps the header and changes the output delimiter to a semicolon.
Input
name,city
Alex , Leeds
Alex,Leeds
Sam,YorkOutput
name;city
Alex;Leeds
Sam;YorkCommon problems and how to fix them
Rows with the same ID remain
Duplicate removal compares every cell, not just one ID column. If another field differs, both rows stay. Case differences also count as different values.
The before-and-after counts exclude a row
With headers enabled, the header is excluded from both counts. Empty lines are skipped during parsing. Turn headers off when the first line is actual data.
I need spaces or formula-like values unchanged
Disable trimming if leading or trailing spaces are meaningful. Formula protection is a separate safety option and may prefix spreadsheet-sensitive cells; review the output before importing it.
Limitations and supported input
Duplicate comparison is case-sensitive and happens after optional trimming. Only whole-row duplicates are removed. Blank lines are skipped. Header rows are preserved and excluded from row counts. Formula protection can add an apostrophe to spreadsheet-sensitive values.
Files must be UTF-8 text and no larger than 10 MiB. Very deep or complex documents may exceed the 15-second processing limit. JSON numbers use JavaScript precision; keep long identifiers as strings.
Your data stays on your device
All parsing and conversion happens in a local browser worker. Your input is not sent to a server or saved in browser storage. Closing or reloading the page clears this workspace. Read our privacy explanation.
GOOD TO KNOW
A little clarity.
Simple tools. Straight answers.
Which duplicate row is kept?
The first occurrence is kept, preserving the original row order.
Will spaces inside a value disappear?
No. Trimming only removes leading and trailing whitespace from each cell.
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