English: World map (Robinson projection) illustrating the residence requirements in years for naturalization across different countries. Countries may have additional requirements or exceptions.

Deep blue indicates countries requiring 2 years of residence, bright blue represents 2.5 years, standard blue signifies 3 years, light blue represents 4 years, and pale blue is used for countries requiring 5 years of residence. Light yellow marks countries with a 7-year requirement, golden yellow represents 8 years, and bright yellow is used for countries requiring 9 years of residence. Bright orange indicates a 10-year requirement, orange represents 12 years, dark orange marks 14 years, and orange-red signifies 15 years of residence. Dark red indicates countries requiring 20 years of residence, very dark red is used for 25 years, deep red for 30 years, and the darkest red marks countries with a 35-year residence requirement. Black indicates countries where naturalization is not allowed. Dark grey indicates where the law does not specify a residence period required for naturalization, application is rather based on other merits and not period of residence. Grey is used for countries where no data is available.

Data source: https://en.wikipedia.org/w/index.php?title=Naturalization&oldid=1246939510#Summary_by_country

Code used to generate the original image: https://github.com/jnton/naturalization-residence-map-generator/