We are planning to be in Frankfurt for 2 or 3 nights, and have 4 children under 12. Where would you suggest we go for night? We're not fancy, but we'd like it to be clean and safe. Thanks in advance!
Meininger and Scandic hotels are known family friendly and often not budget intensive. I do not know how good they are in Frankfurt aM.
You can also look for smaller "Pension"en or Hotel garni which means they are very basic including breakfast.
With 4 kids, you might want to go to the Jugendherberge on the Sachsenhausen side of the river in Frankfurt. They should have a room for 6, and it includes breakfast.
https://www.jugendherberge-frankfurt.de/en/sleeping/families