That depends on fps. I use Photoshop for 5fps gif animated banners for Adwords.
Check also my 5fps GIF banners https://www.adsspirit.com/portfolio/gif-animated-banners/
I use Animate CC and Google web designer. I also can code on my own. HTML5 Banner is like one page web. But time matter i thing.
Check also my design static and animated HTML5, Static and GIF banners https://www.adsspirit.com/
You can have a look some of my works at: https://www.adsspirit.com/portfolio/
I can design beautiful STATIC, GIF and HTML5/Responsive banners for your advertisement needs.