I would like to migrations customer accounts from Magento1 to Magento2 so that customers can login with their account on the new shop. I tried the migration tool but it migrates everything. Is it possible to migrate accounts only ?
Yes, it's possible to migrate everything or just some parts of your database (e.g.: customer accounts, products, orders,...) but you need to customize Magento data migration tool. If you want us to help to migrate your data, please send your request to email@example.com. It will cost from $300-500 and take 3-5 days for Magento data migration service based on how large your database is.