This data quality toolset gives administrators significantly increased power over their data. Use it to mass load, manipulate and verify any data. You can de-dupe data sets (even Leads that duplicate Contacts or Accounts) and compare external data to Salesforce data. DemandTools is exactly what administrators need to manage and control their Salesforce org.
“DemandTools is an enterprise capable suite of data quality modules to control, standardize, verify, de-duplicate, import & generally manipulate Salesforce and/or Force.com data.”