SEO Free Tools That You Should Use

• Google Analytics - This free tool is a must for every seo, online marketers and even to simple webmaster as it can provide you detailed statistics of your site traffic. It's an awesome tool to study your traffic behavior so you can have an insight to how you can improve it more.

www.google.com/analytics/

Here's a few sample list of data that you can get from Google Analytics :

1. Monitor Traffic Sources ( organic search, direct visit, social visit, referral site traffic and more )
2. Track Conversion and Sales
3. Learn Geo-Traffic Location ( what country and city your visitors came from ) 
4. Visitor Engagement (  how long visitors stays on your site, track returning visitors and new visitors )
5. Device use to visit your site
6. Top organic keywords that people search from google
7. Top pages on your site

Google analytics is a very important tool to study your website traffic performance and for you to create adjustments in area that you need to improve on your seo and online marketing campaign.

• Google Webmaster Tool - Probably one of the most important tool that you should use not only because you're an seo but also advisable for every webmaster who wants to have a Google friendly site. It's the best seo tool to collect data and get deeper insights on how google sees your site. Definitely a big help on your on page and off page optimization strategy as it can provide you data like links pointing to your site, index status, internal links, crawl error, top search queries, top pages, html improvement and other helpful feature that will surely help you make a healthy and user friendly website in the eye of google. Using this GA will be a big help to increase your chance to improve your ranking on serps.

https://www.google.com/webmasters/tools/

• OpensiteExplorer.org - Definitely one of my favorite seo tool next to google anaytics and GWT. Also known as a search engine for links. Owned by Moz, opensiteexplorer.org is an awesome online backlink analysis tool to study your competitors link profile.

http://www.opensiteexplorer.org/

Here you can check your site domain authority, page authority which is a very popular metrics among seo's to measure link popularity of a website. Here you can also get interesting data like total inbound link count, linking domains, top pages and more. It's totally free but if you want a much more deeper insights on your site and your competitors, you may upgrade it to paid version.

• Moonsy.com - A site if you want to check important website metrics like google page rank, domain authority, page authority, site age, alexa rank, compete rank, semrush metrics, moz trust, domain availability, google keyword position and other metric that will surely help your website analysis.

• Ahrefs.com -  Just like OpensiteExplorer, Ahrefs is another great free backlink analysis tool that you will surely love. 

https://ahrefs.com/

It can give you data about your backlink count, referring domain, top pages, TLDs referral, types of link you have like no-follow or dofollow link count, new link that your site recently get as well as link that you just lost. It also show details about anchor phrases count and percentage you used on all of your backlinks which is very important to monitor as google hate overused of rich keyword anchor text in backlinks. It's free but you can also upgrade it to professional plan if you want to remove the limitation feature but you just need to pay for it.

• CuteRank Free Edition - Is a free seo sofware tool for you to easily monitor you website's keyword ranking from major search engine like Google, Bing, Yahoo, Ask, Aol

http://cuterank.net/

You can easily regroup your keywords in this software and monitor your site's keyword ranking automatically and manually. It shows detailed report about  your site rank changes over search engine that you choose.

• SeoQuake - It's a free seo browser plug in that you can use to instantly check page rank, alexa rank, domain age, google index count, social counts and other important metrics once you visit a website. 

http://www.seoquake.com/

SEOquake can help you analyze website instantly as it appears right on the top of every website that you visit as long as those website don't block it. It also has 

There are lots of amazing free tools that you can use to help you on your seo strategy. I can't just list it all here since it's too many but here's the a few list if you want more, you can search for it on your own if you want to know it.

Other list of SEO Free Tools that you can use :

1. Google Keyword Planner
2. Majestic Seo
3. Traffic Travis Sofware
4. Semrush
5. Alexa
6.  CopyScape