CSV Tools

Remove Duplicates

Find and eliminate duplicate rows

CSV Input

Try a sample:

Options

Compare by

CSV Output

Deduplicated CSV will appear here...

More Options

CSV Format

Input

Output

Keep

How to Use This Tool

This tool finds and removes duplicate rows from your CSV. You can compare entire rows or choose specific columns to check for duplicates. It runs directly in your browser, so your data is never uploaded anywhere.

The Options panel shows a summary of how many duplicates were found and how many unique rows remain, similar to Excel’s remove duplicates feature.

  1. Provide your CSV — Paste CSV text into the input area, drop a CSV file onto the File tab, or enter a URL on the URL tab.
  2. Choose how to compare — Use “Entire Row” to match rows that are completely identical, or “Select Columns” to match based on specific columns only.
  3. Get your output — Copy the deduplicated CSV to your clipboard or save it as a .csv file.

FAQ

4 questions
Does this tool upload my data?
No. It runs entirely in your browser using JavaScript. Your CSV data is never sent to a server.
Can I compare specific columns instead of the whole row?
Yes. Switch to 'Select Columns' mode and choose which columns to use for finding duplicates. For example, you might want to find rows with the same email address even if other fields differ.
Which duplicate gets kept?
By default, the first occurrence is kept and later duplicates are removed. You can change this to keep the last occurrence instead in the More Options panel.
How do I know how many duplicates were found?
The Options panel shows a summary below the compare settings, telling you exactly how many duplicate rows were found and how many unique rows remain.

More Row Operations Tools

9 tools

Filter Rows

Keep only rows that match your criteria

Sort CSV

Sort rows by any column, ascending or descending

Sample Rows

Pick a random sample of rows from your CSV

First N Rows

Extract the first N rows from your CSV

Last N Rows

Extract the last N rows from your CSV

Slice Rows

Extract a range of rows by start and end position

Add Row Numbers

Add a sequential row number column to your CSV

Reverse Rows

Reverse the order of rows in your CSV

Shuffle Rows

Randomly reorder all rows in your CSV

More CSV Tools

89 tools

Add Header Row

Add a header row to a CSV that doesn't have one

Anonymize Columns

Replace sensitive column values with fake data

Compare Files

Compare two CSV files and highlight the differences

Column Counter

Count the number of columns in your CSV

CSV to Excel

Export CSV data to .xlsx spreadsheets

CSV to YNAB

Convert CSV bank statements into YNAB-compatible import format

CSV Viewer

View and explore CSV files in a sortable table

Extract Email Addresses

Find and extract all email addresses from your text or CSV

Filter Rows

Keep only rows that match your criteria

Merge CSVs

Combine multiple CSV files into one

Remove Columns

Delete one or more columns from your CSV

Column Stats

Get data type, null count, unique count, and common values per column

CSV to Xero

Convert CSV bank statements into Xero-compatible import format

Extract Columns

Keep only the columns you need from your CSV

Excel to CSV

Import .xlsx files and convert to CSV

Extract Phone Numbers

Find and extract all phone numbers from your text or CSV

Find Missing Rows

Find rows in one file that are missing from another

Redact Columns

Mask or remove sensitive values from selected columns

Remove Header Row

Remove the header row from your CSV

Sort CSV

Sort rows by any column, ascending or descending

Split CSV

Break large CSVs into smaller chunks

Calculate Dimensions

Get the row count, column count, and size of your CSV

Change Header Case

Switch headers between camelCase, snake_case, kebab-case, and more

CSV to JSON

Convert CSV files to clean, structured JSON

CSV to QBO

Convert CSV bank transactions into QuickBooks format

Extract URLs

Find and extract all URLs from your text or CSV

Find Common Rows

Find rows that appear in both CSV files

Rename Columns

Change the header names of your CSV columns

Split by Column Value

Split a CSV into multiple files based on column values

JSON to CSV

Convert JSON arrays to downloadable CSV

QBO to CSV

Convert QuickBooks QBO files into CSV format

Remove Empty Rows

Delete rows that are completely empty

Reorder Columns

Rearrange the column order in your CSV

Row Counter

Quick count of rows, columns, and empty cells

Sample Rows

Pick a random sample of rows from your CSV

Add Column

Add a new column with a default value to your CSV

Count Values

Count the number of non-empty values in each column

CSV to QFX

Convert CSV bank transactions into Quicken format

CSV to XML

Transform CSV into well-formed XML documents

Fill Missing Values

Replace empty cells with a default value

First N Rows

Extract the first N rows from your CSV

Find and Replace

Search for values in your CSV and replace them

Last N Rows

Extract the last N rows from your CSV

QFX to CSV

Convert Quicken QFX files into CSV format

Summary Statistics

Get count, mean, min, max, and percentiles for numeric columns

XML to CSV

Convert XML data with repeating elements into CSV

CSV to OFX

Convert CSV financial data into Open Financial Exchange format

CSV to TSV

Convert comma-separated values to tab-separated format

Slice Rows

Extract a range of rows by start and end position

Split Column

Split one column into two columns by a delimiter

Sum Column

Calculate the total of all values in each numeric column

Trim Whitespace

Remove leading and trailing spaces from all cells

Add Row Numbers

Add a sequential row number column to your CSV

Average Column

Calculate the average of all values in each numeric column

Merge Columns

Combine two columns into one using coalesce logic

OFX to CSV

Convert OFX financial files into CSV format

Remove HTML Tags

Strip HTML tags from cell values in your CSV

TSV to CSV

Convert tab-separated data into comma-separated CSV

Count Unique

Count the number of distinct values in each column

CSV to HTML

Generate HTML tables from CSV data for easy web embedding

CSV to QIF

Convert CSV financial data into Quicken Interchange Format

Map Column Values

Replace column values using a visual mapping table

Remove Comments

Remove comment lines from your CSV

Reverse Rows

Reverse the order of rows in your CSV

HTML to CSV

Extract table data from HTML and convert to CSV

QIF to CSV

Convert Quicken QIF files into CSV format

Remove Whitespace

Strip all unnecessary whitespace from your CSV

Shuffle Rows

Randomly reorder all rows in your CSV

Running Total

Add a cumulative sum column to your CSV

Uppercase Column

Convert all values in a column to uppercase

Compress CSV

Minify your CSV by removing unnecessary whitespace and formatting

CSV to YAML

Transform CSV data into clean, readable YAML documents

Lowercase Column

Convert all values in a column to lowercase

Percentage of Total

Add a column showing each row's share of the total

CSV Validator

Check your CSV for formatting errors and structural issues

Rolling Average

Calculate a moving average over a sliding window of rows

Swap Column Data

Swap the data between two columns in your CSV

YAML to CSV

Convert YAML lists into CSV format

CSV to Markdown

Convert CSV data into GitHub-flavored Markdown tables

Duplicate Column

Create a copy of an existing column

Markdown to CSV

Convert Markdown tables into CSV format

CSV to JSON Lines

Convert CSV rows into newline-delimited JSON (JSONL/NDJSON)

JSON Lines to CSV

Convert JSONL/NDJSON data into CSV format

CSV to SQL

Generate SQL INSERT statements from CSV data

CSV to Fixed Width

Convert CSV data into fixed-width column format

Fixed Width to CSV

Convert fixed-width column data into CSV format

CSV to LaTeX

Generate LaTeX table markup from CSV data

Parquet to CSV

Convert Apache Parquet files to CSV format

Feather to CSV

Convert Apache Feather/Arrow files to CSV format