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Remove duplicate CSV rows

Find duplicate CSV records using selected key columns and keep the first or last match.

  1. 1Add files
  2. 2Options
  3. 3Convert
  4. 4Save
No installation · Processed in your browser

Preparing the converter…

Add your CSV filesDrop files here or choose them from your device.Drop here to add your files. Choose CSV files CSVCSVNo fixed byte cap · browser memory and format limits apply
Choose a file to check its format and size.

Related tools

Convert CSV to JSONParse a CSV header and rows into JSON records, choosing the input encoding and delimiter.Convert JSON to CSVExport an array of JSON objects as CSV rows, with an option to flatten nested fields.Convert TSV to CSVRead tab-separated records with the selected encoding and write comma-separated CSV.Convert CSV to TSVChange CSV records to a tab-separated file while parsing quoted CSV fields.Convert XML to JSONParse safe XML and represent its elements and values as a JSON structure.

Supported formats and settings

Input formats
CSV
Output formats
CSV
Per-file limit
Current device memory
Total selected-file limit
Estimated by file count and format
Number of selectable files
1–1

Recommended input total: 8 MiB on mobile / 32 MiB on desktop. Low memory can reduce the effective limit.

Your files are not uploaded to a conversion server. A new result is created in your browser.

How to use this tool

  1. Choose files in CSV format. Maximum files per batch: 1.
  2. Review Key columns (empty for full row), Duplicate row to keep, Ignore surrounding whitespace, then start processing.
  3. Download the CSV result and check its content and quality.

What this tool does

  • Find duplicate CSV records using selected key columns and keep the first or last match.
  • Read CSV input and save the CSV result as a new file.
  • Available settings: Key columns (empty for full row), Duplicate row to keep, Ignore surrounding whitespace, Ignore letter case.

Limitations

  • Trimming whitespace and ignoring case can merge values that you intended to keep distinct.

Frequently asked questions

Remove duplicate CSV rows — What should I check before using this tool?

Trimming whitespace and ignoring case can merge values that you intended to keep distinct.

Which files can I choose?

Choose files in CSV format. Maximum files per batch: 1.

How can I adjust the result?

Key columns (empty for full row), Duplicate row to keep, Ignore surrounding whitespace, Ignore letter case.

Understand the formats

CSV

CSV stores rows of delimited text. Quoted fields can contain commas and line breaks; encoding and header conventions vary between applications.

Use CSV for exchanging a simple table. Select the correct character encoding and inspect the column names before converting to JSON.

Leading zeros, dates and long identifiers can be changed by spreadsheet software when opened. Coverton neutralizes formula-like cells in supported table exports; encoding-only conversion preserves the original text.

When is this useful?

Remove repeated CSV keys after choosing columns and which row to keep. Review records whose other values differ.

Input and result example

repeated order IDs → CSV with retained records

Examples illustrate the workflow; actual size, support and recognition depend on the source and settings.

Related guides

Check CSV and Excel data before importFile conversion and error basics