If you like SEO tools and you’re a fan of free stuff, you’re going to LOVE this list of free SEO tools. The list is organized into 11 categories, and each category broadly describes a popular SEO task (e.g., Backlink Investigation, Keyword Research, SEO Analysis, etc.).
I’ve included a brief overview of each tool’s free functionality (some of the tools are freemium), screenshots, videos, and links to documentation for the more complex tools. Hopefully, this resource will give you everything you need to start mastering these amazing tools.
So without further ado, let’s jump into the list…
Backlink Investigation
For years, your site’s backlink profile played a vital role in your site’s ability to rank well in the search engines. Now, in the post-Penguin era, that backlink profile is more important than ever. With that in mind, the following free SEO tools will help you investigate a site’s backlink profile.
1. Open Site Explorer
After Yahoo! Site Explorer’s untimely demise in 2011, Open Site Explorer (OSE) became one of the most popular backlink checking tools. OSE uses the freemium model, and without an account, you are limited to running 3 reports per day.
The following screenshot shows an example report:
If you register for a free account, you have access to 1,000 backlinks for a given URL, and the first 15 backlinks include additional information such as the link’s anchor text, Page Authority, and Domain Authority. Each report also includes summary information about the requested URL: its Page Authority, Domain Authority, number of linking root domains, and number of total links.2. Majestic SEO Site Explorer
Majestic SEO Site Explorer is another popular backlink checking tool, and like OSE, it uses a freemium model. Without an account, you are only able to access general summary information about a requested URL or domain (e.g., number of referring domains, number of external backlinks, number of referring IP addresses, etc.).
If you register for a free account, you receive additional summary information (e.g., a backlink breakdown), and you also get access to the top 5 backlinks, top 5 referring domains, and top 100 pages (based on the number of referring domains) for your request.
For more information, read Julie Joyce’s Majestic SEO review.
3. Ahrefs Site Explorer
Ahrefs is one of the newest backlink checking tools, but it already has a very loyal user base. Similar to most of its competitors, the tool uses a freemium model.
As a guest, you are allowed to perform 5 requests per day, and if you register for a free account, that allowance increases to 15 requests per day. Each request returns a backlink overview as well as specific information about individual backlinks (for free accounts, only the first 5 backlinks display additional information).
The backlink overview includes information such as the total number of backlinks, the number of referring domains (and a corresponding TLD breakdown), and a breakdown of the backlink types (e.g., text, image, nofollow, etc.).
For a given request, free accounts receive access to the first 500 backlinks. The first 5 backlinks display the link’s Ahrefs rank, source URL, source title, destination URL, anchor text, type, and crawl date. However, the remaining backlinks only display the link’s Ahrefs rank, source URL, and source title.
For more information, check out Eric Covino’s Ahrefs Review.
4. Link Diagnosis
Link Diagnosis is a completely free backlink checking tool, but unless you install the corresponding Firefox extension, you will only receive a limited view of the results (the “lite report”). Without the Firefox extension, the tool displays the first 250 backlinks, along with each backlink’s anchor text, mozRank, Page Authority, and Domain Authority.
With the extension installed, the 250 backlink restriction is removed, and the tool presents each backlink’s title (i.e., the title of the linking page), link type (e.g., nofollow), PageRank, outbound link count, modified outbound link count, and LinkStrength (in addition to the information displayed without the extension).
Server Investigation
When diagnosing an SEO issue, it is often useful to investigate the site’s Web server. Whether it’s identifying a server’s technology stack, uncovering the source of performance bottlenecks, or troubleshooting HTTP headers, the following free SEO tools can help.
5. BuiltWith
BuiltWith provides a technology profile for a given site, which includes information about the site’s server, frameworks, advertising, analytics, JavaScript libraries, and much, much more. You enter a website’s URL, and the tool essentially performs a technology X-ray.
Here’s a screenshot of the tool’s technology profile:
The tool also provides a simple SEO profile, which checks a page’s title, meta description, H1 tag, content keywords, images, response speed, and social sharing.6. Pingdom Full Page Test
Pingdom offers a free online tool that analyzes a URL’s load time. You simply enter a URL, and the tool displays a summary of the page’s load time, size, and number of corresponding HTTP requests.
Here’s a screenshot of Pingdom’s results:
As the screenshot shows, the tool also presents a waterfall visualization that displays the load time and size of each of the page’s objects.7. Google PageSpeed
PageSpeed is a free online tool (plugins are also available) that tests a URL’s load performance. You enter a URL, and then, the tool presents a list of performance-based suggestions (e.g., optimize images, minify JavaScript, etc.), which are categorized into high, medium, and low priority items.8. URI Valet
URI Valet is a free online tool that displays the HTTP headers exchanged during a request for a given URI. The tool also presents a summary of the corresponding HTML’s <head> tags and a breakdown of the various objects (e.g., scripts, images, etc.) that are downloaded when accessing the URI.9. SpyOnWeb
SpyOnWeb identifies multiple sites that probably belong to the same owner. On the backend, the service clusters sites that share an IP address, Google AdSense ID, Google Analytics ID, Yahoo! Publisher Network ID, or Yandex.Direct ID. Then, when you query a website’s URL, the tool presents a list of sites that have been clustered together with that URL using the previously listed information.Website Crawling & Link Checking
One of the best ways to identify SEO-related problems with your site is to crawl its pages and look for issues. These issues can be markup-related (e.g., duplicate titles), or they can be link-related (e.g., broken links).
10. Screaming Frog SEO Spider Tool
The Screaming Frog SEO Spider Tool is a freemium desktop application that allows you to crawl and analyze the pages on your website. The tool is free for the first 500 URI requests and £99/year after that.
For each request, you receive a wealth of information, including the page’s title, meta description, heading tags, image info (e.g., alt text), link info (e.g., are they nofollowed), and much, much more. Rather than bombard you with screenshots, here’s a video that demonstrates the tool’s functionality:
11. Xenu’s Link Sleuth
Xenu’s Link Sleuth is a free desktop application that checks for broken links on your website. The tool also displays page titles and meta descriptions, but its primary purpose in life is to quickly crawl a website and identify the status codes of the site’s links.12. W3C Link Checker
Link Checker is a free online tool that checks the validity of links for a given URL. You simply enter a URL, and then, the tool recursively checks the URL’s links for URI scheme errors, redirects, and error status codes.Content & Markup Analysis
Your site’s on-page ranking factors are derived from the site’s content and markup. Consequently, it’s extremely important that you optimize the content and minimize errors in the markup.
13. SEO Browser
SEO Browser is one of the oldest free SEO tools, but it is still incredibly useful. The tool is 100% free, and it offers two modes: Simple and Advanced. The Simple mode displays a given URL like a text-based Web browser (e.g., lynx). The Advanced mode provides a text-based view of a URL, and it also includes useful information that summarizes the URL’s content (e.g., page title, meta tags, page size, word count, IP address, etc.).14. Copyscape
Copyscape is an online duplicate content detection tool that uses a freemium model. You simply enter a page’s URL, and the tool returns a list of pages that are duplicating the URL’s content. With a free account, the tool only displays the first ten results, and the tool only allows a certain number of monthly requests for any given site (this limit is irrespective of the IP submitting the request).15. W3C Markup Validation Service
The Markup Validation Service is a free online tool that checks the markup validity of the Web document associated with a given URI. You simply enter a URI, and then, the tool checks its correctness (based on the syntax of its document type). Finally, the tool displays an itemized list of errors and warnings (with corresponding line and column numbers) that it finds during the validation process.
Here’s an excerpt from the tool’s validation output:
Keyword Research
When attracting potential customers, it’s important to speak their language. If your site isn’t using the keyword phrases that people are searching for, those people will have a difficult time finding you. Fortunately, a number of free keyword research tools exist.
16. Google AdWords Keyword Tool
The AdWords Keyword Tool is one of the most popular free keyword tools available. The tool gives you three options for querying keywords: (1) input a list of keywords, (2) input a URL, which the tool scrapes to identify keywords, or (3) select from a predefined list of categories.
Once you select a querying method, the tool allows you to slice and dice the results using a variety of filters, match types, and keyword term inclusion/exclusion lists.
To learn more, visit Google’s help page for Using the Keyword Tool. It answers popular questions and offers helpful videos that showcase the tool’s functionality.
17. Wordtracker
Wordtracker is one of the oldest keyword research tools, and it uses the freemium model. With the free version, you enter a keyword phrase, and then, the tool presents up to 100 related keywords, along with estimated search totals.18. Ubersuggest
Ubersuggest is a free online keyword suggestion tool that uses Google Suggest (and other suggest services) to generate a list of related keywords. You simply enter a keyword phrase. Then, the tool adds a letter or digit in front of your phrase and displays the corresponding suggestions.19. Latent Dirichlet Allocation Content Optimizer
LDA Content Optimizer is a free online tool that analyzes a given URL’s content to identify relevant keywords, which are currently missing from the page.
To use the tool, you enter a URL (or a block of content) and a targeted keyword. The tool computes the LDA relevancy score for that URL and keyword, and then, it identifies collocated keywords from top ranking pages that are missing from the given URL (and would improve its relevancy).
Here’s an example of the tool’s results:
Competitive Keyword Analysis
When conducting keyword research, it’s always interesting to see which keywords your competitors are targeting. How much overlap exists between their keywords and yours? Are they targeting keywords that you haven’t considered? The following free SEO tools can help you answer these types of questions.
20. SpyFu
SpyFu is a competitive keyword analysis tool that uses the freemium model. When you enter a domain, the tool displays summary information, which includes the domain’s daily PPC ad budget, the domain’s daily organic SEO traffic value, and a graph of the domain’s historical budget. The tool’s domain report also shows the domain’s top 10 paid keywords, ad competitors, organic keywords, and organic competitors.
When you enter a keyword, the tool presents summary information, which includes the keyword’s CPC, average click count, and search volume. The keyword report also displays the top PPC domains, organic search results, and related terms.
Here’s an epic video that introduces SpyFu:
21. SEMRush
SEMRush is one of the older free SEO tools on this list, and its age is a clear endorsement of its value. The tool focuses on competitive research as well as keyword research. When you enter a domain or URL, you receive a report that includes the corresponding organic keywords, advertising keywords, organic competitors, advertising competitors, and more.
When you enter a keyword, the report presents summary information (CPC, level of competition, average volume, etc.), similar keywords, organic competitors, and advertising competitors.
The tool uses the freemium model, and with a free account, you have access to 10 reports per day (and 10 results for each section of the report). For more information, consult theSEMRush manual. It provides useful videos and detailed descriptions of the tool’s functionality.
Social Discovery
As the social Web becomes more and more popular, it becomes more and more important to leverage it in your daily SEO activities. The following free SEO tools help you quantify social signals, discover popular social content, and identify influential social participants.
22. Shared Count
Shared Count is a free online service (and accompanying API) that presents the most popular social metrics for a given URL. Currently, this list of social metrics is derived from Facebook (likes, shares, and comments), Twitter (tweets), Google+ (+1s), Digg (diggs), Pinterest (pins), LinkedIn (shares), Delicious (bookmarks), and StumbleUpon (stumbles).23. SocialMention
SocialMention is a free social media search engine that aggregates user generated content from 100+ social media sources, including Twitter, Facebook, FriendFeed, YouTube, Digg, and Google. You simply search for a topic, and the search engine will return the most recent results from the social Web, along with descriptive statistics for those results (e.g., sentiment breakdown, top keywords, top users, etc.).
Here’s a screenshot that shows an example of the search engine’s results:
In addition to providing a search interface, SocialMention also offers daily social media alerts and an API.
24. Follower Wonk
Follower Wonk is a Twitter analysis tool that uses the freemium model. The tool is great for identifying influencers, building out personas, or finding outreach targets for guest posts. As a free user, you are able to accomplish three tasks: (1) search Twitter bios for specific keywords, (2) compare the social graphs of up to three accounts, and (3) analyze the social graph characteristics of a single account (e.g., influence of the account, influence of the account’s followings, etc.).PR & Outreach
You don’t have to spend a fortune to receive high quality news coverage or to attract high quality writers to your site. The following tools will help you cultivate relationships with reporters, bloggers, and potential advertising partners… all for the low, low price of FREE!
25. HARO – Help a Reporter Out
HARO is a free online service that allows reporters to connect directly with expert sources. As a reporter, you simply submit a query on HARO’s website, and then, that query will appear with others in an email, which is delivered to the sources. As a source, you simply monitor the stream of daily emails from HARO, and if you see a query that is relevant to your expertise, you can respond to the querying reporter directly. You can also find out about reporter queries by following @helpareporter on Twitter.26. Blogger LinkUp
Blogger LinkUp (BLU) is a completely free service that allows anyone to request guest posts, sources for interviews, and product reviews from a community of users. If you have a request, you submit it on BLU’s website. Then, that request is aggregated with other requests and sent to the community in an email. On the flip side, if you join the free community, you will receive an email every Monday, Wednesday, and Friday that contains the most recent requests. If you see a relevant request, you respond directly to the requester.27. MyBlogGuest
MyBlogGuest is a free community dedicated to helping bloggers write and publish guest posts. Once you sign up for a free account, you receive access to various forums that allow you to introduce yourself to community, search for sites looking for guest posts, and search for bloggers looking to write guest posts. The community also offers a searching mechanism that allows you to search for specific categories, tags, or users.
In addition to the forums, MyBlogGuest provides an Article Gallery and an Infographics Gallery. The former is a database of available guest posts that blog owners can request to publish, and the latter is a collection of infographics that bloggers can include in their content.
Here’s a helpful video that explains the Article Gallery:
28. DoubleClick Ad Planner
Ad Planner is a free online tool that helps you plan your media strategy. Specifically, the tool allows you to find websites that your audience is likely to visit so that you can use those sites for advertising, guest posts, or other outreach opportunities.
You can find these websites by searching based on a given domain (i.e, find sites similar to that domain), or you can search based on specific criteria (e.g., geography, categorical interests, etc.). For more information, watch this quick video overview:
Analytics
Unless you know who is visiting your site and how they’re getting there, you’re basically flying blind. Analytics packages help remove the mystery by giving you actionable information about your site’s visitors.
29. Google Analytics
Google Analytics is one of the most popular free analytics packages available. Once you create an account, you are asked to insert a few lines of JavaScript on your site. After that code is in place, you’ll be able to start monitoring your site’s traffic through the Google Analytics interface.
Currently, the interface is divided into 5 main sections: Audience (information about the people visiting your site), Advertising (information about your site’s advertising campaigns), Traffic Sources (information about where your site’s traffic is originating from), Content (information about your site’s most popular pages), and Conversions (information about your site’s goal completions and sales conversions).
For a quick overview, take the Google Analytics Product Tour, and for a Google Analytics alternative, check out Piwik.
Search Engine Guidance
When optimizing your site for the search engines, it’s a good idea to consult them whenever possible. The following free SEO tools will help you seek guidance from the search engines.
30. Google Webmaster Tools
Google is the most popular search engine in the world, and as a result, Google Webmaster Tools (GWT) is one of the most useful free SEO tools available because it gives you direct access to some of Google’s information about your site.
GWT presents information in 5 categories: Configuration (allows you to configure your GWT account), Health (displays crawling errors or malware found on your site), Traffic (shows search queries, backlinks, and +1s for your site), Optimization (helps you improve your site’s content and indexing), and Labs (experimental features).
For more information, visit Google’s Webmaster Tools Help.
31. Bing Webmaster Tools
Bing isn’t as popular as Google, but Bing Webmaster Tools (BWT) is still an extremely valuable tool because it allows you to view your site through the eyes of yet another search engine.
BWT displays information in 5 main sections: Dashboard (shows traffic, index, and crawl summaries), Crawl (displays crawled pages and errors), Index (presents indexed pages and backlinks), Traffic (identifies traffic sources and CTRs), and Keywords (Bing’s keyword research tool).
For more information, visit Bing’s Webmaster Tools Help
32. blekko
Update [8/16/2012]: blekko no longer offers free SEO data (it’s now $99/month – insane, I know.) For now, I’m keeping them on the list for nostalgic purposes, in hopes that they eventually come to their senses.
SEO Analysis
The last category includes free SEO tools that analyze a given Web page and assign an SEO score to it based on various criteria.
33. WooRank
WooRank offers an instant website review. The tool uses the freemium model, and without a premium account, you are limited to generating only one free report per week (but you can still query reports that have been previously generated).
Here’s an excerpt from WooRank’s report:
The tool’s report is currently divided into 13 sections: Top 5 Priorities, Visitors, Social Monitoring, Mobile, SEO Basics, SEO Content, SEO Links, SEO Keywords, SEO Authority, SEO Backlinks, Usability, Security, and Technologies.
