Below is a growing list of possible ranking factors that affect how a website or page ranks in the Google search results. This list has been compiled by Rand Fishkin at seomoz. These, along with a black box of Google ranking factors are given different weight as to how much or how little they affect rankings and SEO. The ones that have a lighter weight are tweaked daily/hourly (based on a machine learning model). These daily/hourly based tweaks are in response to the spammer community to try and combat what they are doing to manipulate the search results. The heavier weighted variables are usually tweaked in large roll outs such as the current Panda Update (update to remove thin, low quality content and websites from the search results). As you can see it there are many factors that SEO has to balance to help build rankings, and why every thing that is done to a site, even the smallest change, can have a butterfly effect on a large set of these factors and influence rankings.
On-Page Factors
Keyword in Title
Keyword First Word(s) in Title
Keyword in Title 2X
Keyword in Title 3X+
Keyword in H1
Keyword First Word(s) in H1
Keyword in H1 2X
Keyword in H1 3X+
Keyword in H(x) (2+)
Keyword in URL
Keyword in Meta Keywords
Keyword in Meta Description
Keyword in Meta Tag (non Description/Keyword)
Keyword in First 10 Words on Page
Keyword in First 100 Words on Page
Keyword in First 500 Words on Page
TF*IDF
Keyword Density
# of Keyword Repetitions
LDA Score of Body Content
LDA Score of Page Title
Document Length in Words
Document Length in Characters
Reading Level of Document
# of Images in Document
# of Images >30x30px in Document
# of Internal Links in Document
# of External Links in Document
# of Followed Internal Links in Document
# of Followed External Links in Document
# of Nofollowed Internal Links in Document
# of Nofollowed External Links in Document
# of Total Links in Document
# of Total Followed Links in Document
# of Total Nofollowed Links in Document
# of External Links to DA 80+ Domains
# of External Links to DA <40 Domains
# of External Links to DmT 6+ Domains
# of External Links to DmT <3 Domains
Highest # of External Links to any Single Domain
Presence of Link to Privacy Policy on Page
Page Size in KB
Download Speed
Presence of Video Content
Presence of External iFrame
Presence of Internal iFrame
Presence of Date
(If Date Exists) Recency of Date
Presence of AdSense on the Page
Presence of Microsoft Powered Ads on the Page
Presence of Google Ad Network Powered Ads on the Page
HTML/XHTML Version in Markup
W3C Code Validation
# of Errors According to W3C Code Validation
Presence of HTML Tables
Presence of a Link to a Twitter Account
Presence of a Link to a Facebook Account
Presence of a Link to a page on *Googlecom
Presence of a Link to a page on *Microsoftcom
Presence of Foul/Adult Language URL Length in Characters
Number of Trailing Slashes in URL (folder depth)
Hyphen Use in URL
Underscore Use in URL
http vs https
presence of ?= in URL string
presence of 2+ ?= in URL string
Presence of Rel=Canonical on page
Is page the homepage of the domain
Does page have >100 followed links
Does page have >100 total links
Does page have >300 followed links
Does page have >300 total links
Does the page have breadcrumbs showing in Google’s SERPs (vs just the URL)
Is the page https (secure server)
Does the URL contain “www”
Using WordPress platform
Using Tumblr/Posterous/Blogger/Typepad/etc platform
Page-Specific Link Factors
# of external pages linking
# of internal pages linking
# of domains linking
# of external pages with followed links
# of domains with followed links
# of external pages with nofollowed links
# of domains with nofollowed links
ratio of followed/nofollowed linking pages
ratio of followed/nofollowed linking domains
# of linking domains with exact match anchor text
# of external linking pages with exact match anchor text
# of external followed linking pages with exact match anchor text
# of external, nofollowed linking pages with exact match anchor text
# of internal linking pages with exact match anchor text
# of internal followed linking pages with exact match anchor text
# of internal, nofollowed linking pages with exact match anchor text
# of followed linking domains with exact match anchor text
# of nofollowed linking domains with exact match anchor text
# of linking domains with partial match anchor text
# of external linking pages with partial match anchor text
# of external, followed linking pages with partial match anchor text
# of external, nofollowed linking pages with partial match anchor text
# of internal linking pages with partial match anchor text
# of internal, followed linking pages with partial match anchor text
# of internal, nofollowed linking pages with partial match anchor text
# of followed linking domains with partial match anchor text
# of nofollowed linking domains with partial match anchor text
# of unique anchor text phrases in all links to the page
mozRank
External mozRank (mozRank from External Pages Only)
Internal mozRank (mozRank from Internal Pages Only)
Google Toolbar PageRank
# of 301 redirects to the page
# of pages rel=canonical(ing) to the page
mozTrust
External mozTrust (TrustRank from External Pages Only)
Internal mozTrust (TrustRank from Internal Pages Only)
# of linking domains with DmR 0-29
# of linking domains with DmR 30-49
# of linking domains with DmR 50-69
# of linking domains with DmR 70-89
# of linking domains with DmR 9+
# of linking domains with DmT 0-29
# of linking domains with DmT 30-49
# of linking domains with DmT 50-69
# of linking domains with DmT 70-89
# of linking domains with DmT 9+
# of unique c-blocks with links
# of unique c-blocks with followed links
# of unique c-blocks with nofollowed links
# of unique followed link c-blocks with exact match anchor text
# of unique nofollowed link c-blocks with exact match anchor text
# of unique followed link c-blocks with partial match anchor text
# of unique nofollowed link c-blocks with partial match anchor text
# of same c-block root domains with links
# of same c-block root domains with followed links
# of same c-block root domains with nofollowed links
Page-Specific Social Factors
Has a link to the page been “tweeted”
Has a link to the page been “tweeted” in the last 24 hours
Has a link to the page been “tweeted” in the last 7 days
Has a link to the page been “tweeted” in the last 14 days
Has a link to the page been “tweeted” in the last 30 days
How many “tweets” contain a link to the page
How many “tweets” contain a link to the page in the last 24 hours
How many “tweets” contain a link to the page in the last 7 days
How many “tweets” contain a link to the page in the last 14 days
How many “tweets” contain a link to the page in the last 30 days
How many Facebook “shares” has the page received
How many StumbleUpon upvotes has the page received
Domain (Non-Link) Factors
Character length of domain name
Presence of hyphens in domain name
Number of hyphens in domain name
Presence of numeric characters in domains name
Exact match domain name
Word match domain name (all query terms are in domain, but not in exact order)
Phrase match domain name (all query terms are in domain, but with other words/characters)
Partial match domain name (only some of the query terms are in the domain name)
Exact match subdomain
Word match subdomain (all query terms are in subdomain, but not in exact order)
Phrase match subdomain (all query terms are in subdomain, but with other words/characters)
Partial match subdomain (only some of the query terms are in the subdomain)
Date of first domain registration
Date of last domain registration renewal
Public or private setting on domain registrar contact information
Number of other domains owned by registrar (if available)
Presence of subdomain (vs just xyzcom)
Geographic location of IP Address
Compete Rank
Alexa Rank
Quantcast Rank
Included in Google Trends for Websites
Included in DoubleClick Ad Planner
Opted-In to Quantcast “Quantified”
edu TLD extension
gov TLD extension
com TLD extension
(any/all) TLD extensions
Root Domain Link Factors
# of external pages linking
# of internal pages on domain w/ external links
# of domains linking
# of external pages with followed links
# of domains with followed links
# of external pages with nofollowed links
# of domains with nofollowed links
Domain mozRank
Domain mozTrust
Domain included in DMOZ
Domain included in Yahoo! Directory
Domain linked-to by Wikipedia
# of pages on Domain linked-to by Wikipedia
DomainJuice (total of mozRank on pages on the domain)
# of gov domains with links to the site
# of gov domains with followed links to the site
# of gov domains with nofollowed links to the site
# of pages from gov domains with links to the site
# of pages from gov domains with followed links to the site
# of pages from gov domains with nofollowed links to the site
# of edu domains with links to the site # of edu domains with followed links to the site
# of edu domains with nofollowed links to the site
# of pages from edu domains with links to the site
# of pages from edu domains with followed links to the site
# of pages from edu domains with nofollowed links to the site
# of internal pages on domain w/ 10+ linking root domains
# of pages on domain according to Google site: query
# of links on domain according to Google link: query
Google Toolbar PageRank of Homepage
# of 301 redirects to the page
# of pages rel=canonical(ing) to the page
# of linking domains with DmR 0-29
# of linking domains with DmR 30-49
# of linking domains with DmR 50-69
# of linking domains with DmR 70-89
# of linking domains with DmR 9+
# of linking domains with DmT 0-29
# of linking domains with DmT 30-49
# of linking domains with DmT 50-69
# of linking domains with DmT 70-89
# of linking domains with DmT 9+
# of unique c-blocks with links
# of unique c-blocks with followed links
# of unique c-blocks with nofollowed links
# of same c-block root domains with links
# of same c-block root domains with followed links
# of same c-block root domains with nofollowed links
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