Free Tools: 1. Anchor Text Over Optimization Tool http://www.removeem.com/ratios.php Worried about Google's Penguin algorithm hitting you for over-optimized anchor text? Simply type in your URL for a full report of which links might raise flags. 2. Bing Webmaster Tools http://www.bing.com/toolbox/webmaster Similar in function to Google Webmaster Tools, Bing offers a suite of interesting research tools and resources for webmasters. 3. Bitly https://bitly.com/ Most people use Bitly for URL shortening, but the real power of this platform comes from its analytics. 4. Boomerang http://www.boomeranggmail.com/ Boomerang lets you follow up on emails, even when you forget. Great for link building or any time you send a lot of emails. 5. Buffer https://bufferapp.com/ Optimize your online social media sharing. Buffer allows you to share with your audience at the optimal times for greater visibility. 6. BuiltWith http://builtwith.com/ Use BuiltWith to discover what technology nearly any website was, well, built with. Great for competitive intelligence as well. 7. Buzzstream Tools Suite http://tools.buzzstream.com/link-building Link Building, Tools Suite, Email Most people know Buzzstream as an outreach platform, but they also offer a number of free link-building tools. This company gets it. 8. Caption Tube http://captiontube.appspot.com/ Video Free and easy resource used to create captions for YouTube. Helps with usability and offers viewers a readable transcript. 9. CircleCount http://www.circlecount.com/ Social, Analytics Google+ analytics ramped up. Free resource to track your followers and analyze your shares. See how many followers you've gained over time. 10. Content Strategy Generator Tool http://seogadget.com/content-strategy-generator-tool-v2-update/ Content This tool from SEOgadget helps you plan your content strategy intelligently, using keyword research and estimating your audience size. 11. Convert Word Documents to Clean HTML http://word2cleanhtml.com/ Content, Productivity Despite the rise of Google Docs, Word still dominates much of the world. Copying and pasting has always been a hurdle, but this tool makes it easy. 12. Copyscape http://www.copyscape.com/ Content Copyscape serves both as a plagiarism checker and a duplicate-content checker. Great to use if your content has been distributed across the web. 13. Domain Hunter Plus http://domainhunterplus.com/ Link Building This magic extension for Chrome not only helps you find important broken links, but also tells you if the links point to an available domain. 14. Easel.ly http://www.easel.ly/ Infographics Free tools for creating and sharing inforgraphics. The templates allow anyone to create a professional-looking graphic. 15. Email Format http://email-format.com/ Email, Productivity Email Format helps you find the proper structure for thousands of companies and organizations across the web. 16. FindPeopleonPlus http://www.findpeopleonplus.com/ Social The ultimate Google+ directory that's great for research, outreach, and link building. Sort by keywords, profession, country, and more. 17. Frobee Robots.txt Checker http://www.frobee.com/robots-txt-check Robots.txt, Technical SEO Many robots.txt files contain hidden errors not easily visible to humans. Run your file through this tool and you never know what you'll discover. 18. GetListed https://getlisted.org/ Local, Moz This awesome local SEO tool scores your local SEO visibility and gives you actionable next steps to raise your score. 19. Google Keyword Planner http://adwords.google.com/keywordplanner Keyword Research The tool to replace Google's popular keyword tool has been derided by some, but still offers data not available anywhere else. 20. Google Analytics http://www.google.com/analytics/ Analytics The most popular of all the analytics tools available, Google Analytics continually innovates and sets the standard. 21. Google Analytics API https://support.google.com/analytics/answer/1008004?hl=en&ref_topic=1008008 API, Analytics The Google Analytics API is great for building custom reports and tools, and also for pulling data straight into Excel or Google Docs. 22. Google Map Maker http://www.google.com/mapmaker Local Among other things, Google Map Maker allows you to contribute to public map information, which may be shared and incorporated into Google Maps. 23. Google PageSpeed Insights https://developers.google.com/speed/pagespeed/insights Speed Tools, data, and insights to improve your page speed. Page speed is correlated with better rankings and user engagement, so this matters. 24. Google Public Data http://www.google.com/publicdata/directory Content Drawing on vast public databases, Google public data offers a great starting point for content research, infographics, and more. 25. Google SERP Snippet Optimization Tool http://www.seomofo.com/snippet-optimizer.html Technical SEO, CRO That SEO Mofo! Use this tool to see how your snippet may appear in Google's search results. Add structured data, review stars, and more. 26. Google Structured Data Testing Tool http://www.google.com/webmasters/tools/richsnippets Structured Data, Technical SEO If you use Schema.org microformats or any other type of structured data, this tool will verify your markup. 27. Google Trends http://www.google.com/trends/ Keyword Research See what's trending in Google search results and view keyword search popularity over time. A must for trends. 28. Google Webmaster http://www.google.com/webmasters/ Tools Suite, Diagnostic The interface recently received an overhaul, and Google Webmaster remains a must-have resource of diagnostic and health tools for site owners. 29. IFTTT https://ifttt.com/ Productivity IFTTT stands for IF This, Then That. The tool allows you to create automatic triggers between various apps, like Gmail and Twitter. 30. Infogr.am http://infogr.am/ Infographics A great free Infographics resource that allows you to easily create graphics and data visualizations. 31. Internet Marketing Ninjas SEO Tools http://www.internetmarketingninjas.com/tools/ Tools Suite The Ninjas are some of the best SEOs and online marketers out there, and they've put some of their best tools online for free. 32. Linkstant http://www.linkstant.com/ Link Building This nifty analytics tool alerts you anytime someone links to your website. Great for outreach and intelligence gathering. 33. Linksy.me Email Guesser http://linksy.me/find-email Email, Link Building Need to send an email, but you don't have the recipient's address? Type in what you know and this nifty tool will help you figure it out. 34. MailTester.com http://mailtester.com/ Email Need to send an email to an untested address, but you don't want to spam them? Check it first with this mail tester to verify. 35. MozCast http://mozcast.com/ SERP Tracking, Moz Want to know if Google is testing its algorithm this week? MozCast gives you a daily weather report to track changes in the SERPs. 36. MyBlogGuest http://myblogguest.com/ Link Building, Content Guest blogging is still alive and thriving. MyBlogGuest helps you find the good opportunities out there. 37. Panguin Tool http://www.barracuda-digital.co.uk/panguin-tool/ Analytics This awesome tool connects with your Google Analytics account to help you see if and when you've been hit by Google Algorithm updates. 38. Pingdom http://tools.pingdom.com/fpt/ Speed Pingdom offers an entire suite of speed tools to help analyze page load, DNS issues, and connectivity. 39. Piwik http://piwik.org/ Analytics Piwik is a lightweight web analytics solution, and a great alternative to Google Analytics. 40. Rank Checker for Firefox http://tools.seobook.com/firefox/rank-checker/ Rank Tracking This light and easy desktop tool checks rankings with the click of a button. Quick, easy and free. 41. Rapportive http://rapportive.com/ Email, Link Building, Productivity Rapportive works with your Gmail inbox to give you near-instant rich contact information for almost everyone you want to reach. A must-have for marketers. 42. Remove Duplicate Items http://ontolo.com/tools-remove-duplicates Productivity Ontolo offers a suite of link building software and a few helpful productivity tools for link builders. The remove duplicates tool solves a common problem. 43. Robots.txt Checker http://tool.motoricerca.info/robots-checker.phtml Robots.txt, Technical SEO Use robots best practices and discover hidden errors in your robots.txt files that may cause search engine crawling problems. 44. Schema Creator http://schema-creator.org/ Structured Data, Technical SEO Everyone loves using Schema.org, but the microformats are difficult to write by hand. This generator from the folks at Raven simplifies the task. 45. Scraper for Chrome https://chrome.google.com/webstore/detail/scraper/ Productivity If you've never scraped a webpage, you're missing out. Scraper for Chrome puts the power of simple web scraping in your hands without the need for code. 46. Seer Toolbox http://www.seerinteractive.com/seo-toolbox/ Tools Suite, Analytics, Link Research SEER opened up its internal toolbox for everyone in the world to use. These are the same tools used in-house at SEER, and they rock. 47. SEO Toolbar http://tools.seobook.com/seo-toolbar/ Tools Suite, Toolbar, Technical SEO On of the most popular tools available, The SEO Toolbar puts a ton of information at your fingertips including backlinks and competitive research. 48. SEO Tools for Excel http://nielsbosma.se/projects/seotools/ Tools Suite, Analytics, Social You don't need to be an Excel ninja to use Niels Bosma's SEO Tools for Excel. This plugin does so many things many SEOs won't work without it. 49. SEOgadget Links API http://seogadget.com/api/ API, Link Research The SEOgadget Links API lets you easily gather not only backlink data but contact information as well. A huge time saver. 50. SEOgadget Tools http://seogadget.com/tools/ Tools Suite This suite of tools from the Gadget lab includes several Excel plugins, a content strategy generator, and more. 51. SEOQuake http://www.seoquake.com/ Toolbar, Tools Suite, Technical SEO More raw data than any other SEO toolbar out there. 52. SharedCount http://www.sharedcount.com/ Social, Analytics Want to know how any piece of content was shared socially across the major services? This is the tool to use. 53. SharedCount API http://www.sharedcount.com/documentation.php API, Social Harnessing the combined statistics of Google+, Twitter, Facebook, and more, the SharedCount API puts a ton of social data at your fingertips. 54. Similar Page Checker http://www.webconfs.com/similar-page-checker.php Content, Technical SEO Use this tool to check for duplicate content issues. The Similar Page Checker will give you a score of how closely the HTML of two pages resemble each other. 55. Sitemap Generators http://code.google.com/p/sitemap-generators/wiki/SitemapGenerators Sitemaps Google offers a slew of free, top-notch sitemap generators. Most of these live on your server and generate new sitemaps automatically. 56. Social Authority API https://followerwonk.com/social-authority API, Social How much reach and social authority do your followers have? How about the people you're trying to connect with? The free Social Authority API will tell you. 57. Social Crawlytics https://socialcrawlytics.com/ Social, Analytics Social Crawlytics allows you to conduct competitive research by showing you your competitors' most-shared content. Lots of other features as well. 58. Social Mention http://www.socialmention.com/ Social Social mention offers real-time social media search and analysis. Enter a search term and see who's sharing what, right now. 59. Text Cleaner http://www.textcleanr.com/ Content Some of the best tools solve the simplest problems. Text cleaner cleans up all kinds of text formatting when copying and pasting between aplications. 60. Ubersuggest http://ubersuggest.org/ Keyword Research Every SEO loves Ubersuggest for its ease of use and wealth of keyword research ideas. Utilizing the power of Google Suggest, it returns hundreds of potential results. 61. URI Valet http://urivalet.com/ Technical SEO A great tool for digging into server headers, canonical information, analyzing redirect problems and more. 62. Virante SEO Tools http://www.virante.org/seo-tools Tools Suite Virant offers a number of high quality SEO tools to the public. These are often the same tools developed for the Virant team, opened up for public use. 63. Wayback Machine http://archive.org/web/web.php Competitive Intelligence Want to see the history of your website or your competitor's site? The Wayback Machine allows you to step back in time and track important changes. 64. WebPagetest http://www.webpagetest.org/ Speed Quick and easy website speed tool. Offers suggestions for improving performance. 65. Wordle http://www.wordle.net/ Content Create beautiful word clouds. Great for visualizations, graphics, and research. 66. Wordstream Free Keyword Tools http://www.wordstream.com/free-keyword-tools Keyword Research, Tools Suite In addition to its paid offerings, Wordstream offers a suite of free keyword tools offering access to thousands of keyword suggestions. 67. Xenu's Link Sleuth http://home.snafu.de/tilman/xenulink.html Diagnostic, Technical SEO Winner of the ugliest-SEO-tool-on-the-planet award, Xenu is also one of the most useful. Crawl entire sites, find broken links, create sitemaps, and more. 68. XML-Sitemaps.com http://www.xml-sitemaps.com/ Sitemaps XML-Sitemaps offers probably the easiest sitemap creation solution anywhere. Great for smaller sites when you need a sitemap in minutes. 69. Yahoo Pipes http://pipes.yahoo.com/pipes/ Content, Productivity A great mashup tool that combines different feeds into content and other magical creations. Used for link building and whatever you can dream of. 70. Yoast WordPress SEO Plugin http://yoast.com/wordpress/seo/ Technical SEO If you could only choose one WordPress plugin for you site, the first would be from Yoast, and so would the second. This one sets the standard. 71. YouTube Analytics https://www.youtube.com/analytics Video, Analytics Offers video-specific analytics for YouTube videos. A must-have for YouTube video publishers. Free and Paid 72. Ahrefs https://ahrefs.com/ Link Research, Link Building One of the more popular link research tools, Ahrefs offers a large index and nice anchor text distribution charts. Mostly a paid tool, but they offer some free data. 73. Banana Tag http://bananatag.com/ Email Banana Tag allows you to track your emails after you send them. For example, check your email open rates from Gmail. 74. CloudFlare https://www.cloudflare.com/ Speed How do they make CloudFlare free? It works both as a CDN and a security service to provide your website with speed and safety. 75. Followerwonk https://followerwonk.com/ Social, Analytics, Moz Perhaps the coolest thing about Followerwonk is the ability to track your followers. Smart SEOs also use it for outreach and research. 76. Keyword Eye http://www.keywordeye.com/ Keyword Research Keyword eye adds a twist to keyword research by adding rich visualizations ? essential when you want to move beyond keywords to valuable concepts. 77. KnowEm http://knowem.com/ Social KnowEm allows you to check 100's of social profiles at once to check availability. Looking for the perfect brand name? Check KnowEm first. 78. Majestic SEO http://www.majesticseo.com/ Link Research, Competitive Intelligence, Link Building You've probably seen Majestic SEO link charts all over the Internet. Great crawling technology combined with several free options make for great link research. 79. Majestic SEO API http://blog.majesticseo.com/general/majestic-seo-api-now-explained/ API, Link Research Majestic makes much of its backlink data available for free via its API. 80. MozBar http://moz.com/tools/seo-toolbar Tools Suite, Toolbar, Moz The standard SEO toolbar for legions of marketers, the MozBar allows you to perform over 50 key tasks right from your browser. Highly recommended. 81. Mozscape API http://moz.com/products/api API, Link Research, Moz Companies everywhere incorporate the Mozscape API into their own products, but it's also available to individuals, and much of the data is free. 82. nTopic http://www.ntopic.org/ Content nTopic is one of the few proven methods for giving your content a relevancy score and offering keyword suggestions to improve it. 83. Open Site Explorer http://www.opensiteexplorer.org/ Link Research, Moz, Competitive Intelligence, Link Building When Google and Yahoo started removing backlink data from the public, Moz built Open Site Explorer to fill a huge need. See backlinks, anchor text, popularity metrics and more. 84. Piktochart http://piktochart.com/ Infographics A cute and easy infographic generator. No experience required. 85. RowFeeder https://rowfeeder.com/ Social, Analytics RowFeeder allows you to track social usernames, hashtags and keywords and load that information into Excel for easy social media monitoring. 86. Screaming Frog http://www.screamingfrog.co.uk/ Diagnostic, Technical SEO A powerful website crawling tool with a ton of features and customizations. A must-have for most serious SEOs. 87. Searchmetrics Visibility Charts http://suite.searchmetrics.com/en/research SERP Tracking, Competitive Intelligence Track the search visibility of any website, in addition to tracking winners and losers in Google's search results. 88. SEMrush http://www.semrush.com/ Tools Suite, Keyword Research, Competitive Intelligence The paid and organic keyword data offered by SEMrush is often scary good and comprehensive. Also great for researching competitors' ads. 89. SERPmetrics http://serpmetrics.com/flux/ SERP Tracking, Competitive Intelligence SERPmetrics flux charts track the flux for US search results across Yahoo, Bing and Google over a 30-day period. A paid API is also available. 90. SimilarWeb http://www.similarweb.com/ Competitive Intelligence Impressive competitive intelligence across a number of online industries. Competitor website stats are hard to come by, but Similar Web does a good job. 91. StatCounter http://statcounter.com/ Analytics Free, quick, and lightweight analytics solution. Often used by those who want to avoid using Google Analytics for privacy reasons. 92. Trello https://trello.com/ Productivity Project management and tracking made simple. Used and endorsed by Moz. 93. Whitespark Local Citation Finder https://www.whitespark.ca/local-citation-finder/ Local Finding local citations is key to local SEO. Whitespark offers a number of free and paid solutions to find the local citations to rise above the competition. 94. Whois Lookup http://whois.domaintools.com/ Competitive Intelligence Find registration, contact, and administrative information for any domain. 95. Wistia http://wistia.com/ Video The king of online video, Wistia offers SEO-friendly solutions for video hosting. Both free and low-cost options available. Free Trials 96. Moz Analytics http://moz.com/products Tools Suite, Diagnostic, Moz, Rank Tracking, Social The flagship of the Moz software suite, Moz Analytics offers a dashboard of all your important marketing data in one place with actionable analytics for better marketing. 97. Optimizely https://www.optimizely.com/ A/B Testing, CRO Easy A/B testing and analytics to help you move toward success in your CRO efforts. 98. Raven http://raventools.com/ Tools Suite, Diagnostic, Content, Social Raven offers a classic suite of SEO, content, and research tools popular with many marketers. 99. Visual Website Optimizer https://visualwebsiteoptimizer.com/ A/B Testing, CRO Visual Website Optimizer allows you to run A/B tests with a simple online editor that lets you test content without knowing code. 100. Wordtracker http://www.wordtracker.com/ Keyword Research A powerful keyword research suite used by many top marketers, Wordtracker offers a generous free trial option. What's your favorite free tool?