Generate CRM test data with duplicates built in

Fictional contacts in your CRM’s import columns with the duplicates you choose.

Use in Claude

Every name and company is invented. Nothing is written to any CRM.

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

Generated HubSpot contacts with two duplicate pairs highlighted and a Group column naming which rows belong together and how each copy was disguised.

Test data that looks like the real mess

A sandbox full of tidy rows proves nothing. Real duplicates hide behind a second email or a reversed name or a missing field. A dedupe that passes on clean test data fails on Monday.

This tool seeds the duplicates the way people create them and can label the truth for scoring.

Then run the real thing on it

Import the file into a test portal. Point a duplicate search at it. Count what was found against the groups you seeded.

Dedupely finds the seeded duplicates in your sandbox and shows every merge in Merge History.

A sandbox scorecard: 45 seeded duplicate groups, 44 found, 1 missed, 0 false matches.

Use it from a script or an AI agent

Use in Claude 
POST https://dedupe.ly/tools/api/test-data-generator
{ "rows": 500, "duplicateRate": 0.15, "shape": "hubspot", "labelGroups": true }

MCP  https://dedupe.ly/tools/mcp   (tool: generate_test_data)
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.

"The data in our CRM is much cleaner thanks to this App. Easy to use and relatively inexpensive."
H Chitty

H Chitty

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"I do recommend! A++ Pretty easy to use. Adequate reporting. SUPERB CUSTOMER SUCCESS!"
Alina T

Alina T

Sales Operations Specialist, FieldBee

51–100 employees
"Great tool that works as promised. Great customer support - Nestor was super helpful onboarding."

R McNaught

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"It prioritizes merging while keeping key data. Highly recommended for anyone using Pipedrive integration."
John K

John K

Head of Marketing, David J Anderson School of Management

Pipedrive MarketplacePipedrive user
"The app worked great and helped me a lot with hundreds of duplicates in Pipedrive."
Samo J

Samo J

Founder & CSO, TapHome

Pipedrive MarketplacePipedrive user
"Superior deduping logic with excellent support - highly recommend for cleaning up messy HubSpot records."
M Weppner

M Weppner

"Dedupely was incredibly easy to set up, and the support team replied almost instantly each time I reached out. In just a few

Yuliya

Pipedrive User

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

D Wright

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"The application works great and [...] their customer support was responsive and helped me get on the right track!"

Shawnee K

Salesforce User

Salesforce AppExchangeSalesforce AppExchange
"Worked as expected and Nestor at Customer support was extremely helpful walking me through some nightmare duplicate issues."

DiBlasio S

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"I was really pleased with Dedupely. It's highly configurable and works well when used manually or for automated deduping."

Laura R

Salesforce User

Salesforce AppExchangeSalesforce AppExchange
"It couldn't have been much easier to connect to HubSpot and run my first dedupe."

Emily K

Mercy Housing

HubSpot MarketplaceHubSpot user
"It did more than I expected. Support is great!"

Paweł S

Pipedrive User

Pipedrive MarketplacePipedrive Marketplace
"Dedupely helped us to quickly de-duplicate hundreds of records, with a level of transparency that gives you confidence..."

Grattan H

Pipedrive User

Pipedrive MarketplacePipedrive Marketplace
"Our customers want to achieve great results fast. Everybody at HubSpot already knows what Dedupely can do..."
Scott B

Scott B

VP Platform Ecosystem, HubSpot

"This tool made a week long project take a few hours. Definitely a go-to for deduplication processes."

Burchard J

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"It took away the huge headache we had of merging over 27,000 duplicate contacts."
Sean B

Sean B

Managing Director, Legal CPD

"Most of all, our team has been impressed by the way the Dedupely Customer Success team consistently goes above and beyond."

Isaac J

Salesforce User

Salesforce AppExchangeSalesforce AppExchange
"Great support. They are on top of things, and answer questions very quickly."

Larry D

Pipedrive User

Pipedrive MarketplacePipedrive Marketplace
"Works really well, support is A++++++"

Andy G

Pipedrive User

Pipedrive MarketplacePipedrive Marketplace
"We had 300k records in our CRM. Despite the large amount, Dedupely was perfect. The support was especially outstanding."
Simon W

Simon W

Tillhub

~50 employees
"Worked very simply and effectively and suited my budget [...] Very happy to recommend a good app and integration."
Allan R

Allan R

Co-founder & Managing Director, Target3D

11–50 employees
"Dedupely was huge in improving the quality of my CRM database. It saved me hours of manual merging."
Marco S

Marco S

Information Systems Manager, Efecte

~200 employees
"Fantastic time saver with great filters - auto and bulk merging made so much easier!"
A Team

A Team

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"It helped us clean up a giant mess of duplicates after migrating to HubSpot from our old CRM."

J Eddie

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"Perfect solution that delivers exactly as promised. Does exactly what we need it to. Great tool."

A Grogan-Crane

HubSpot User

HubSpot MarketplaceHubSpot Marketplace
"In a matter of maybe 30 minutes [...] Dedupely automatically took care of my dupes and merge needs. So happy I found it."

Wasmer D

HubSpot User

HubSpot MarketplaceHubSpot Marketplace

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