If you have spent time in a high-risk area or area of virus variant of concern, you are required to travel directly to your home or other appropriate accommodation immediately after arriving in Germany and to stay there for ten days (quarantine). You are not permitted to receive any visitors. Violations constitute an administrative offence and may be punished by a fine of up to 25,000 euros.

A list of current high-risk areas and areas of variant of concern can be found at website of the Robert Koch Institute

Travellers who have spent time in high-risk areas must remain in quarantine for ten days. If, before the ten days have elapsed, you submit proof of vaccination or of recovery from COVID-19 to https://www.einreiseanmeldung.de, you may end your quarantine at the time you submit the necessary proof. Alternatively, after the fifth day in quarantine, you may reduce the quarantine period by submitting proof of a negative test result. Children under the age of 12 who are entering Germany from high-risk areas may end quarantine automatically after five days even without submitting proof of a negative test result.

Travellers who have spent time in areas of virus variant of concern must remain in quarantine for 14 days. In this case, there is no option to end quarantine sooner, even for people who have been vaccinated or who have recovered from COVID-19.

The quarantine requirement will remain in effect until at least 3 March 2022.

You will find more information here:

Updated information for travellers

Questions and answers on COVID-19 testing when travelling to Germany

Information on testing (in German)