According to Backlinko, there are over 200 Search Engine Ranking Factors

"Some are proven. Some are controversial. Others are SEO nerd speculation. But they鈥檙e all here." - Google鈥檚 200 Ranking Factors: The Complete List by Brian Dean

The Periodic Table of SEO Success Factors

Search Engine Land - The Periodic Table Of SEO Success Factors

2016 Searchmetrics General Search Ranking Factors

After 2016, Searchmetrics started publishing detailed industry reports to show the difference in factors by industry.

• Travel
• eCommerce
• Finance
• Health
• Media

Search Engine Ranking Factors 2015
Expert Survey and Correlation Data

"Every two years, Moz surveys the opinions of dozens of the world's brightest search marketers and runs correlation studies to better understand the workings of search engine algorithms."

On Mar 23, 2016 Google's Andrey Lipattsevm stated that links, content and RankBrain are the top three ranking signals in Google's search algorithm.

Now we know: Here are Google's top 3 search ranking factors - Barry Schwartz, Search Engine Land

Pagerank Rankbrain

• RankBrain is a machine learning artificial intelligence system ...
• If RankBrain sees a word or phrase it isn鈥檛 familiar with, the machine can make a guess as to what words or phrases might have a similar meaning and filter the result accordingly, making it more effective at handling never-before-seen search queries or keywords. - Wikipedia

Learn more about Rankbrain

• How to Use Google RankBrain in SEO
• FAQ: All About The New Google RankBrain Algorithm
• Artificial intelligence is changing SEO faster than you think
• Optimizing for RankBrain... Should We Do It? (Is It Even Possible?)
• SEO Trek: The Search for Google RankBrain* [New Data]
• Content Marketing and SEO
• The four pillars of the future of SEO
• What is Google Rankbrain?

Ranking Factor Categories

Content

• Quality writing
  Are you smarter than a 5th grader? Your content should be.
• Keyword Research
  Is your writing using enough keywords from the topic your searchers are looking for?
• Freshness
  Is the content new, or has it been updated recently?
• Images, Video, News related to content or vertical
  Does the content provide other value beyond words about the topic?
• Does the content answer questions?
  For informational searches, people are entering questions into Google. Answer them!
• Negative Factor - Thin: Does the content lack substance?

Content

Images

A third of all searches performed in Google are for images and 12.5% of SERPs show Image Pack results

• Drupal core Responsive Image module
• Require Alt text on all image entities
• Drupal Image Optimize (or ImageAPI Optimize) module

Architecture

Is the site easily crawlable?

• Well thought out, keyboard navigable menu
• Breadcrumbs with Schema.org Markup
• Drupal Sitemap module (HTML)
• Drupal Simple XML Sitemap module (D8)
• Drupal XML Sitemap module (D7)
• Friendly URLs from Drupal Pathauto module

Architecture

Is the site easily crawlable?

Have you ever crawled your site? Use a tool like Screaming Frog SEO Spider to see what you have actually created, and build reports on areas where you can improve.

Architecture

Does the site work on mobile?

Make sure you use a responsive theme, and it passes the Google Mobile-Friendly Test

Consider adding Accelerated Mobile Pages (AMP) structured markup to your site. Drupal AMP module.

Architecture

No Duplicate content

• Redirect module
• Metatag module
  • Set Canonical URL
  • Set Robots noindex, nofollow tags where needed

Architecture

Does the site load quickly?

• So many different types of Caching available in Drupal.
• Drupal Advanced CSS/JS Aggregation Module and the Get 100 on PageSpeed Insights tutorial
• CDN like Cloudflare, Fastly, etc...
• Responsive Images/Small image sizes in Image Presets

Architecture

Does the site contain keywords in the url?

• Use the Pathauto module to set friendly URLs
  • Set default patterns for all content types
  • Configure global settings
  • Train content editors to manually configure for page

Architecture

Is the site secure?

• Use HTTPS with an SSL certificate for all sites here on out.
• Keep core and all modules up to date
• Limit server access, and keep server up to date if not managed
• Require strong passwords - Drupal Password Policy module

Architecture

Cloaking

Negative Factor - Cloaking: Don't show different content to humans that you show to search engines.

HTML

Does the Page Title contain keywords?

Properly set up html title using the Drupal Token module's values in the Metatag module

HTML

Does the Meta Description describe the pages?

• Add a "Teaser" field which can be used with the Token and Metatag modules for meta description and search results.
• Same goes for a Feature Image field, used for OG/Twitter Card Meta Images.

HTML

Does the site use Structured data?

Schema.org markup in content & theme templates

              

  WAAY-TV
  ABC
  SD
  PST
  

    ABC
  

              
            

HTML

Does the site use Structured data?

JavaScript Object Notation for Linked Data (JSON-LD)
using the Drupal Schema.org Metatag module

Now is the time to add every Schema.org markup you can. Every site should have:

• Website/Site Search
• Organization
• Person
• BreadcrumbList
• SiteNavigationElement
• VideoObject

In addition to the content specific Schemas you should add for Google Search features.

HTML

Does the site use Structured data?

The Open Graph Protocol enables any web page to become a rich object in a social graph.

Add using the Drupal Metatag Open Graph Submodule

Debug using the Facebook Debugger

HTML

Does the site use Structured data?

Using Twitter Cards you can attach rich photos, videos and media experiences to Tweets.

Add using the Drupal Metatag Twittercard Submodule

Debug using the Twitter Card Validator

HTML

Does the site use Structured data?

Accelerated Mobile Pages (AMP)
Allows publishers to create mobile optimized content on Google.
AMP Drupal Module

HTML

Proper use of headers

• Proper, ordered use of h1, h2, h3
• Remove h1 from WYSIWYG since it is set in template
• In the theme, remove h3 from block headers, to reserve for content use.
• Negative Factor - Stuffing: Don't overuse keywords just for Search engines.
• Negative Factor - Hidden: Don't use CSS or JS to hide words you want to be ranked for.

Offsite Factors

Trust

• Authority: Is the site a trusted authority? External links
• Engage: Bounce Rate
• History: Has the domain/site been around?
• Negative Factor - Piracy: Flagged for pirated content
• Negative Factor - Ads: Too many ads above the fold

Offsite Factors

Links

• Quality of links
  Each link is graded on where it comes from, quality of domain, URL, place on page, etc...
• Keywords in links
  Are the keywords for the topic in the link to your page?
• Quantity
  How many links does your piece of content need?
• Negative Factor - Paid Links: Don't buy links!
• Negative Factor - Spam: Don't allow Comment/Forum Spam

Offsite Factors

Personal

• Country: Same country as searcher
• Locality: Same city/town
• History: Has the user visited the site before?
• Social: Has the site been shared in circles?

Offsite Factors

Social

• Reputation: Is your site respected on social networks?
• Shares: Content shares

Tools for those responsible for Content

• Research
• Create & Analyze
• Report & Refine

Research

Competitor/Topic Analysis

• Alexa
• Buzzsumo
• iSpionage
• Majestic
• Moz Open Site Explorer
• SEMrush
• SimilarWeb

See also: Robbie Richards' The Best SEO Tools: 143 SEO Experts Cast Their Votes (Plus Leaderboard).

Create & Analyze

Tools to analyze content

• Real-time SEO for Drupal
• Real-time SEO for Drupal (Node Preview Sandbox)
• Readability Score
• Readability Analyzer
• Searchmetrics Content Experience

Report & Refine

Tools to report on performance

• Google Analytics
• Google Search Console
• Matomo (Formerly Piwik)
• Bing Webmaster Tools

Tips & Tools for Developers

• Google Defines Best Practices
• Google Structured Data Testing Tool (Schema)
• Google Structured Data Markup Helper (Schema)
• Google PageSpeed Insights
• Google Mobile-Friendly Test
• Google Email Markup Tester
• Google Search Console
• Google Amp Test
• Google Lighthouse
• TechnicalSEO.com
• WebPageTest

Google Search Quality Raters

• Google contracts with over 10,000 search quality raters worldwide to evaluate its search results.
• Quality raters themselves have no bearing on the rankings of the sites they rate.
• Google Search Quality Evaluator Guidelines (160 Page PDF)