I don't think you'll find a total free service that does that.
I am from TIBCO team. I would like to introduce TIBCO Clarity.
You can try TIBCO Clarity for free.https://clarity.cloud.tibco.com/landing/index.html
It has a really powerful and robust de-duplication function.
You can customize your match strategies by columns or by swappable columns or by columns against to a thesaurus table, and then use them to discover duplicate records from any incomplete or partially similar records, even from records in different languages.
In addition, It has deep integration with both Salesforce and Marketo. It can help you directly update and remove duplication data in your salesforce and Marketo account.
I think you should disclose your past and/or present affiliation with TIBCO when posting endorsements.