Insulation Garage Windows

Has anyone tried caulking? My garage windows are not properly insulated and I was wondering if caulking would work. I came across the idea through this article https://www.clerawindows.com/blog/low-cost-ways-to-insulate-your-windows-and-doors-this-winter/. I not in a situation to replace the windows. Can someone suggest me a budget solution?

Without knowing what type of windows you have, it's a guess. Vinyl clad, wooden, metal, single pane, double pane? What is your exterior of your house, brick, siding etc? Where do you propose to caulk?