Getting a taxi from Arlanda airport to downtown Stockholm is the quickest way to reach Stockholm city. It is fast, secure and reliable. There are several companies that operate in Stockholm but beware NOT of using a Taxi without any marked sign of Taxi.
Top three Taxi companies in Stockholm are:
They are biggest operator of Taxi in Stockholm. They charge more than 400Kr for getting to Stockholm from Arlanda airport. You can read more on their website: https://www.sverigetaxi.se/priser
They are most popular and trustworthy in all companies. Their fares are very competitive and their service is extremely fast. You can book the taxi on https://www.taxikurir.se/stockholm
Like most of other taxi companies, they are also fast and reliable. Make sure to check their prices first, as it can vary based on which part of Stockholm you are going. You can read more about them on https://www.taxistockholm.se/sv/