Here are some popular keyword tools that can help you with keyword research, analysis, and optimization:

1. Google Keyword Planner 

   • A free tool that helps you find keywords related to your business and see estimates of the searches they receive and the cost to target them.

2. Ahrefs Keywords Explorer

   • A comprehensive keyword research tool that provides keyword suggestions, search volume, keyword difficulty, and click-through rates.

3. SEMrush

   • Offers a robust keyword research tool that provides keyword suggestions, competitive analysis, and insights into keyword trends.

4. Moz Keyword Explorer

   • A user-friendly tool that provides keyword suggestions, search volume, and difficulty scores, along with SERP analysis.

5. Ubersuggest

   • A free tool that provides keyword suggestions, search volume, and competition data, along with content ideas based on keywords.

6. Keyword Tool

   • A versatile tool that generates keyword suggestions from Google, YouTube, Bing, Amazon, and more, based on a seed keyword.

7. Long Tail Pro

   • Focuses on long-tail keywords and provides keyword competitiveness scores, making it easier to find less competitive keywords.

8. KWFinder

   • A user-friendly tool that helps you find long-tail keywords with low SEO difficulty, along with search volume and trends.

9. AnswerThePublic

   • A unique tool that visualizes search questions and phrases related to your keywords, helping you understand user intent.

10. SpyFu

    • A competitive analysis tool that allows you to see the keywords your competitors are ranking for and their ad spend.

11. Serpstat

    • An all-in-one SEO platform that includes keyword research, competitor analysis, and rank tracking features.

12. Keyword Surfer

    • A Chrome extension that provides keyword data directly in Google search results, including search volume and related keywords.

13. Soovle

    • A keyword suggestion tool that aggregates suggestions from multiple search engines, including Google, Bing, Amazon, and YouTube.

14. Keyword Snatcher

    • A desktop application that generates thousands of keyword ideas from various sources, including Google and eBay.

15. Google Trends

    • A tool that shows the popularity of search queries over time, helping you identify trending keywords and topics.