keyword clustering tool - SERP Analysis

https://www.ryrob.com/keyword-cluster/

https://seoscout.com/tools/keyword-grouping

https://thruuu.com/topic-cluster-content-strategy/free-keyword-grouping-tools/

https://www.keysearch.co/tools/keyword-cluster-tool

https://app.contadu.com/tools/keywords-grouper

https://keywordclustering.zenbrief.com/

https://www.keywordinsights.ai/features/keyword-clustering/

https://www.semrush.com/blog/keyword-manager-clustering-tool/

https://www.reddit.com/r/SEO/comments/1fidve4/what_tools_do_you_use_for_clustering_keywords_if/

https://ahrefs.com/blog/keyword-clustering-tools/