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Private browser utility / Developer

Free CSV Deduplicator

Runs entirely in your browser - no upload, no sign-up.

Live workspaceLocal processing

CSV source

Paste data or choose a CSV, TSV, or text file.

or drop a file here
5 MB, 100,000 rows, and 500 columns max
Your deduplication workspace will appear herePaste CSV, choose a file, or load the example to inspect its columns and matching rules.
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csv deduplicate / browser utility
01 / Overview

What is a CSV deduplicator?

A CSV deduplicator removes repeated records from comma-separated or delimited data. Compare complete rows or choose the columns that identify one record, decide whether the first or last match survives, and download a clean CSV. Your source stays in the browser throughout the process.

02

How to use

  1. 01
    Add the source

    Paste CSV text, choose or drop a local file, or load the worked example.

  2. 02
    Check the structure

    Confirm the detected delimiter and whether the first row contains column names, then analyze the data.

  3. 03
    Define a duplicate

    Select all columns for identical rows or choose the ID, email, or field combination that identifies one record.

  4. 04
    Choose the survivor

    Keep the first or last matching row, optionally ignore case or surrounding spaces, then remove duplicates.

  5. 05
    Review and export

    Check the removal count and preview before copying or downloading the complete deduplicated CSV.

03

Who it's for

  • Marketing teams keeping one contact per email before a list import or campaign send.
  • Operations teams removing overlapping orders or customer records from merged exports.
  • Analysts collapsing repeated observations by an ID or a combination of key fields.
  • Developers cleaning fixtures, logs and migration files while preserving text values.

This tool parses quoted cells before it compares rows, so a comma or line break inside a field cannot shift the deduplication key. It accepts comma, semicolon, tab and pipe separators, an optional UTF-8 byte-order mark, and both LF and CRLF records.

Case folding and edge-space trimming affect the comparison key only. The surviving row is exported exactly as parsed, including its original capitalization and spaces. This makes the cleanup rule visible without silently normalizing the source values.

FAQ

Is my CSV uploaded?

No. File reading, delimiter detection, CSV parsing, duplicate comparison, preview and export all happen in your browser. The page does not send the rows to a conversion service. You can clean customer, order or research exports without transferring the source file to CanDoYa.

Is the CSV deduplicator free?

Yes. You can paste or open data, choose matching columns, compare exact or normalized keys, keep the first or last record, and copy or download the result without payment or sign-up. The displayed size limits only protect browser responsiveness.

How large a CSV file can I deduplicate?

The browser tool accepts up to 5 MB, 100,000 data rows and 500 columns. It stops with a specific message instead of truncating the output. For a larger export, split the file or use a streaming desktop workflow with enough memory.

Can I remove duplicates based on one CSV column?

Yes. Analyze the source, clear the column selection, then choose the email, ID or other field that defines a record. You can also select several columns. Two rows are duplicates only when every selected key value matches under the chosen case and spacing rules.

Which duplicate row does the tool keep?

You choose. Keep first preserves the earliest row for each matching key. Keep last preserves the final row, which is useful for append-only exports where later records contain newer values. In both modes, the surviving rows stay in their original source order.

Can the comparison ignore capitalization and extra spaces?

Yes. Ignore case treats values such as Ada and ada as the same key. Trim surrounding spaces treats a value ending in a space as its unpadded form. These options change comparison only; the text in the surviving row is not rewritten.

Does it handle quoted commas and line breaks?

Yes. The parser understands double-quoted fields, doubled quote characters, delimiters inside quotes and line breaks inside quotes. It also detects malformed quoted input and asks you to repair it instead of splitting the record at the wrong character.

Does CSV deduplication find near matches or typos?

No. This tool performs deterministic equality matching on the selected fields, with optional case and edge-space normalization. It does not use fuzzy matching, punctuation removal or name similarity. Review those uncertain records separately so a loose rule does not merge different people or items.