What both licenses allow
CC BY 4.0 and CC BY-SA 4.0 both permit copying, commercial use, and adaptations. Both require appropriate attribution, a license link, and an indication of changes.
Where ShareAlike changes the answer
CC BY-SA requires a shared adaptation to use CC BY-SA 4.0 or a license Creative Commons has designated as compatible. CC BY does not impose that same adapter-license condition.
Choose based on the downstream goal
Use CC BY when broad reuse and flexible downstream licensing matter most. Use CC BY-SA when adaptations should remain available under reciprocal open terms.
Put it into practice
Check your planned use
Select the exact license and use case to open a permanent result page.
Open compatibility checker