Some free SEO tools, you may need

[william1194]

Keyword Research
1. Google AdWords Keyword Tool: adwords.google.com/KeywordPlanner
2. Wordtracker: https: wordtracker.com/
3. Ubersuggest: ubersuggest.io/
4. Latent Dirichlet Allocation Content Optimizer: ntopic.org/writer.php

Backlink Investigation
1. Open Site Explorer: moz.com/researchtools/ose/
2. Majestic SEO Site Explorer: fr.majestic.com/
3. Link Diagnosis: linkdiagnosis.com/

Website Crawling & Link Checking
1. Screaming Frog SEO Spider Tool: screamingfrog.co.uk/seo-spider/
2. Xenu’s Link Sleuth: home.snafu.de/tilman/xenulink.html
3. W3C Link Checker: validator.w3.org/checklink

Content & Markup Analysis
1. SEO Browser: seo-browser.com/Optimization Tools - SEO Browser
2. Copyscape: copyscape.com/
3. W3C Markup Validation Service: validator.w3.org/

Server Investigation
1. BuiltWith: builtwith.com/
2. Pingdom Full Page Test: tools.pingdom.com/
3. Google PageSpeed: developers.google.com/speed/pagespeed/insights/
4. URI Valet: urivalet.com/
5. SpyOnWeb: spyonweb.com/

[sadianisar]

Other SEO tools are:

small seo tools
backlink watch
SEO site checkup

[Cary Burn]

Fantastic! I am much glad to get the info from here. However, i know about another SEO tools which is good too. You can take a look here https://zenseotools.com

Hope that help!

[Astrosameer]

Impressive ! Thanks for share such post.

[davidwarner033]

William has given information is more helpful to search Engine optimizers. through these tools, we can analyze the complete website health Report.

[Angeljoe]

1. Webmaster Tool
2. Google Analytics

[rajeshparmar]

I am using this 2 tools Lsigraph and Gtmetirx for Keyword research as well as checking website performance.