BYTETOOLS

CSV Cleaner & Deduplicator

Clean CSV online: remove duplicate rows, trim whitespace, drop empty rows and normalise the delimiter. See before/after counts — 100% in your browser.

Drop a .csv file here or click to browse
  • Removes exact duplicate rows
  • Trims leading and trailing whitespace from fields
  • Drops fully empty rows
  • Normalises the delimiter between comma, semicolon and tab
  • Before and after row-count statistics
  • 100% private — cleaned in your browser

How to use the CSV Cleaner & Deduplicator

  1. 1

    Paste your CSV, or drop a .csv file to load it.

  2. 2

    Choose the input and output delimiters.

  3. 3

    Toggle the steps you want: trim, remove duplicates, drop empty rows.

  4. 4

    Click Clean CSV to process the data.

  5. 5

    Compare the before/after counts, then copy or download the result.

About the CSV Cleaner & Deduplicator

The ByteTools CSV Cleaner tidies messy CSV in one pass. It removes duplicate rows, trims stray whitespace from every field, drops fully empty rows, and can normalise the delimiter — then shows you the before and after row counts so you can see exactly what changed.

All cleaning runs locally in your browser with JavaScript, so your CSV is never uploaded to a server. That keeps mailing lists, exports and other sensitive data private while you dedupe and standardise it for import.

It is ideal before loading a file into a database, CRM or spreadsheet, where duplicate or padded rows cause errors. Each cleaning step is a toggle, so you can dedupe only, trim only, or run the full clean, and the quoting-aware parser keeps fields with commas or newlines intact.

Frequently asked questions

How does the CSV cleaner detect duplicate rows?

After optional trimming, rows are compared field by field and any row identical to one already kept is removed. Only the first occurrence of each unique row survives, so the order of your data is preserved.

Will trimming whitespace break fields that need spaces?

Trimming only removes leading and trailing spaces from each field; spaces inside a value are kept. If you need to preserve outer spacing, simply turn the trim option off before cleaning.

Can I change the delimiter while cleaning?

Yes. Set the input delimiter to match your source file and the output delimiter to whatever you need. The cleaner reads with one and writes with the other, re-quoting fields as required.

What counts as an empty row?

A row is considered empty when all of its fields are blank or contain only whitespace. With 'Drop empty rows' enabled these are removed, which is useful for stray blank lines left by exports.

Is my CSV uploaded to be cleaned?

No. The entire clean-up runs in your browser with JavaScript, so your file is never sent to a server and nothing is stored or logged.

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