Popular keyword research tools?

[floridabioclean]

Google Adword Keyword Planner tool, Microsoft Bing Ads Intelligence, Wordtracker's Free Basic Keyword Demand.

[RH-Calvin]

Google keyword planner is the best free tool for high quality keyword research. They help to provide various keyword suggestions for your domain, and selecting the right keywords will help to rank your website higher in search results.

[daikaads]

Keyword Planner and SEMRush are the popular keyword research tools.

[sinelogixtech]

In my opinion, they are:
Adwords(Keyword planner)
Keywordtool.io
Uber suggest
Google related keywords
Ahrefs
Keyword ranktracker
Semrush
Buzzsumo
Long tail pro