Question: I'm looking for a solution that can help me with keyword research and clustering to optimize my content for search engines.

For keyword research and clustering, Keyword Insights is a great option. This AI-based tool lets you generate and cluster keywords, visualize search intent, and create content briefs with more depth and context. It offers tools like keyword discovery, search intent analysis and topic cluster creation, and is great for content marketers and SEO pros who want to work more efficiently and produce better content.

Another top contender is Swiftbrief, an all-in-one SEO tool that includes keyword research, keyword clustering and a brief generator with data-driven insights. It uses a hierarchical keyword categorization approach for consistent clustering results and comes with a content editor and keyword suggestions. Swiftbrief offers three pricing options, including a free tool suite that doesn't require sign-up.

Scalenut is another good option, offering a suite of tools for content creation and optimization. It includes a keyword planning tool, NLP key terms and real-time SEO score auditing. Scalenut is geared for SEO strategists, content creators and agencies, and offers a variety of pricing options, including a free 7-day trial.

If you prefer a more automated approach, WriterZen is an all-in-one SEO content workflow tool. It includes tools like Topic Discovery, Keyword Explorer and an AI-Assistant for content creation. WriterZen also offers a plagiarism checker and team management, so it's good for both individual content creators and teams.