Remove duplicates from a CSV file

Pick the columns that decide a match and download the clean file.

Use in Claude

Free for files up to 2,000 rows and 10 runs a day. Sign up for Dedupely to go further.

A CSV of contacts with two rows for Ellis Crosby highlighted as a duplicate pair, the match set to Email, and a Download CSV button.

Match on the columns that matter

A spreadsheet dedupe compares whole rows. One extra space or a capital letter hides the duplicate. The same contact survives twice.

This tool matches on the columns you choose and ignores case and punctuation.

Stop cleaning the same export twice

The duplicates came from a CRM. Next month’s export has them back. A clean file does not clean the source.

Dedupely merges the duplicates inside your CRM and keeps new ones out.

Three monthly contact exports each with a couple of hundred duplicates found, and below them the CRM with Auto Merge running weekly and no duplicates waiting.

Use it from a script or an AI agent

Use in Claude 
POST https://dedupe.ly/tools/api/csv-dedupe
{ "csv": "Email,Name\n...", "columns": ["Email"] }

MCP  https://dedupe.ly/tools/mcp   (tool: dedupe_csv)
Docs https://dedupe.ly/tools/api/openapi.json

OpenAPI document · API index · llms.txt

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Get started for free

20 free trial merges and as much free support as you need to get your duplicates under control.

"Incredibly effective at tackling massive duplicate data cleanup - exactly what we needed."

D Wright

HubSpot User

HubSpot MarketplaceHubSpot Marketplace

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