Best Keyword Tool for Amazon SEO?

[Butter_Man]

A brain

[Mr_PBpro]

Well you will find a lot of options online. Some are free like Google keyword planner, keywordtool.io and some will be paid after some trial days like SEMrush or Ahrefs. Only thing which will help you would be your understanding and interest towards the niche you will choose.

[SEOpunk]

Helium 10

[kaushikpr]

I use sonar-tool
Easy to use and traffic data is accurate

[brokeasfuck277]

Keyword tool.io,Amazon Keyword Tool for free chrome extension

[m_elabbassi]

for me the best tool i use its alexa platforms,
for free you can use Neilpatel