DataDoctor

Runs entirely in your browser — no uploads, no saved snippets, no public links.

Paste a file, inspect the issues, export reviewed output.

CSV dedupe export

Remove Duplicates from CSV

Paste a CSV file, choose the columns that define a duplicate, then download the deduplicated CSV (with a duplicate-only export for review).

Paste CSV, load the customer sample, or upload a local file.

Next workflow

Continue the preflight

CSV Cleaner

Remove duplicates or incomplete rows after review.

CSV Data Quality Checker

Profile broader CSV quality risks.

CSV Validator

Check parse errors before dedupe.

After the tool runs

Remove Duplicates from CSV review guide

Use the tool above first. The supporting notes below help you interpret the result, fix the right issues in the right order, and choose the next DataDoctor tool without pushing SEO content above the actual task.

Best input

exporting a clean deduplicated CSV after selecting the columns that define a repeated record.

Output to keep

Save the original file, the issue report and the reviewed export as separate files.

Next check

After structural and quality issues are visible, run a platform checker or schema validator before upload.

What it checks

Remove Duplicates from CSV for real data work

Remove Duplicates from CSV should sit before the import screen, not after a failed upload. It turns hidden spreadsheet problems into a checklist you can review row by row.

  • Duplicate key selection
  • First occurrence retention
  • Deduplicated CSV output
  • Duplicate-only export

Fix these first

Common errors to review before downstream work

Most failures come from small file issues that become expensive only after an API call, import job or spreadsheet cleanup. Fix blocking errors first, then re-run the same tool before moving forward.

  • Deduplicating by the first column by accident
  • Treating similar records as identical
  • Ignoring case or whitespace when it matters
  • Deleting before exporting a review file

Recommended workflow

Run the check in this order

Treat any downloaded output as a reviewed candidate. Keep the source CSV unchanged so you can reconcile removed rows, duplicate groups or missing values later.

  1. Step 1

    Paste the CSV

  2. Step 2

    Select the dedupe key

  3. Step 3

    Download duplicate rows for audit

  4. Step 4

    Download the deduplicated CSV only after review

How to interpret a passing result

A pass means this specific preflight did not find the issues listed above. It is not a guarantee that the target system will accept every row, field, custom mapping or account-specific rule.

Do not clean, deduplicate or drop rows before parser errors, required columns and duplicate-key logic are clear.