According to the 2020 U.S. Census, only one city in Alaska has a population exceeding 50,000: Anchorage (291,247).
The original source listed seven "cities," but the others fall well below 50,000:
Alaska uses the term "city" for various municipal classifications (home rule, first class, second class). Many are consolidated city-boroughs (e.g., Juneau, Sitka) covering huge land areas but with small populations. The 50,000 threshold is a standard urban benchmark—only Anchorage meets it.
The Anchorage metropolitan area (~400,000) contains over half the state's population. Fairbanks and Juneau are regional hubs but remain under 50k within city limits.