Google Trends : How do people search for your brand? When do searches spike? What about your competitors? The Google Trends tool uses real-time search data to help you gauge consumer search behaviors over time.
Google Adwords Keyword Planner : Keyword Planner is a free AdWords tool for new or experienced advertisers that’s like a workshop for building new Search Network campaigns or expanding existing ones. You can search for keyword and ad group ideas, see how a list of keywords might perform, and even create a new keyword list by multiplying several lists of keywords together. Keyword Planner can also help you choose competitive bids and budgets to use with your campaigns.
Robots.txt Tester : The robots.txt Tester tool shows you whether your robots.txt file blocks Google web crawlers from specific URLs on your site. For example, you can use this tool to test whether the Googlebot-Image crawler can crawl the URL of an image you wish to block from Google Image Search. Open robots.txt Tester.
HTML / XHTML Validator : Verbose Output. Check. This validator checks the markup validity of Web documents in HTML, XHTML, SMIL, MathML, etc. Flattr us!The W3C validators are hosted on server technology donated by HP, and supported by community donations. Donate and help us build better tools for a better web.
Search Console : Google Search Console (previously Google Webmaster Tools) is a no-charge web service by Google for webmasters. It allows webmasters to check indexing status and optimize visibility of their websites. As of May 20, 2015, Google rebranded Google Webmaster Tools as Google Search Console.
Google Analytics : Google Analytics is a freemium web analytics service offered by Google that tracks and reports website traffic. Google launched the service in November 2005 after acquiring Urchin. Google Analytics is now the most widely used web analytics service on the Internet.
Mobile Friendly Tool : Mobile friendly test tool to give webmasters an analysis if their websites are mobile friendly on a page-by-page basis. Examine your webpage and get instantaneously your mobile friendly test report from this tool.
Page Speed Tool : Scanning your webpages with the page speed test tool is a smart way to pinpoint issues that may negatively impact the website.
CSS Validator : The W3C CSS Validation Service is a free software created by the W3C to help Web designers and Web developers check Cascading Style Sheets (CSS). It can be used on this free service on the web, or downloaded and used either as a java program, or as a java servlet on a Web server.
Structured Data Testing Tool : Test markup — Structured Data Testing Tool. The Structured Data Testing Tool (SDTT) provides a variety of ways to develop, test, and modify your structured markup. You can load markup into the tool either directly or by supplying a URL.