There are lots of tools for seo, like webmaster tools, analytics, ahrefs, keyword planner tools and copy scape.
Google webmaster
Google adwords
Google analytics
Google Adword Keyword Planner, SEO Quake, Google Webmasters and and Google Analtics are the best tool for SEO.
These are the best SEO tool for Google Webmasters , Google Keyword Planner , Ahrefs , SEMRush
There are many tools(free and paid)available which are useful for SEO.But Google Analytics and webmaster tools provided by Google are really helpful in knowing the problems with a website and thus helps in improving the performance of a website.
Best tool for SEO:
SEO Quake Toolbar
Hootsuite
Google Trends
Moz
Google Webmaster tool, google analytic tool
SEO tools help to optimize your website better and rank them higher in search results. The most used tools are:
Google keyword planner
Google analytics tool
Google webmaster tool
Google Adwords
Ahrefs
Copyscape
Moz SEO tools
Google Webmaster tool is best one.