- Google structured data test tool - Test your microdata markup and see examples
- AHrefs - Backlinks searcher and SEO reporter
- Sem Rush - Complete tool to analyse website keywords
- Open Link Profiler - Discover who is creating backlinks to your site
- ContentStudio - Discovery niche-relevant and engaging content and have it shared on your social media channels.
- Open graph debugger - Open graph online debugger
- Keywordtool.io - Keyword searching online tool for google, youtube, appstore and bing
- HTML5 outliner - Check the header structure for your website
- Moz seo toolbar - SEO addon with many funcionalities
- Complete List of HTML Meta Tags
- Google trends - Discover the global trend topics from google
- WebPagetest - Test your website performance
- Loader.io - Cloud-based - Load testing
- Page speed test by Google
- Google mobile friendly - Test your site mobile compatibility according to google
- Google Search Console - Measure your site's Search traffic and performance, fix issues, and make your site shine in Google Search results
- GT Metrix - Measure your site's Page Load Time, Total Page Size and Total # of Requests
- Seobility - Seobility is an all-in-one SEO software offering useful tools such as website crawling, Google rank tracker, backlink checker, continuous monitoring and whitelabel reporting
- Keyword.com – Track, pinpoint and validate your SEO efforts with real-time accurate rank tracking
- Prerender – Prerender serves 100% cached versions of your web pages to search engine bots that have problems executing JavaScript
- Applinks documentation - Use meta tags to create deeplinks for your apps
- Schema.org full list documentation - Full list of recipes from schema.org
- Guidelines for webmasters - Google guidelines for webmasters
- Open graph protocol - Meta tags protocol used by Facebook
- Enabling Rich Snippets for Products
- JSON-LD Schema Markup Generator for SEO - A utility to build schema markup using JSON-LD instead of inline. Can be used with GTM or anywhere on the page.