If you are visiting the UK, you can enter the country with either a Swedish passport or national identity card. The travel document should be valid for the whole of your stay.
From 1 October 2021, you will not be able to enter the UK with your national identity card unless you have a pre-settled or settled EUSS status. More info here.
If you are planning to study, work or stay for a long time you might need to apply for a visa prior to your travels. More information this via this link.
Find extended travel advice for the UK in the Swedish section.
The ban on entry to Sweden from countries outside the EU/EEA ceased to apply on 1 April 2022. This means that the requirement to present vaccination and test certificates when entering Sweden was removed. More information here.
Since 18 March 2022, you do not need to take any COVID-19 tests or quarantine on arrival in England, irrespective of your vaccination status. More information here.
More information about travelling to the UK from Sweden after Brexit here.
Please see the rules for travelling to England with children here.